Pharmaceutical dosage form comprising 6'-fluoro-(N-methyl- or N,N-dimethyl-)-4- phenyl-4',9'-dihydro-3'H-spiro[cyclohexane-1,1'-pyrano[3,4,b ]indol]-4-amine

FIELD OF THE INVENTION

The invention relates to a pharmaceutical dosage form for preferably oral administration twice daily, once daily or less frequently, which contains a pharmacologically active agent according to general formula (I)

wherein R is -H or -CH _3l or a physiologically acceptable salt thereof.

The pharmacologically active agents according to general formula (I) can also be referred to as 6'-Fluoro-(N-methyl- or N.N-dimethyl- -phenyl^'.Q'-dihydro-S'H-spirotcyclohexane-l .l '- pyrano[3,4,b]indol]-4-amine. Unless expressly stated otherwise, this term also includes the physiologically acceptable salts.

BACKGROUND OF THE INVENTION

The pharmacologically active agents according to the invention are known from the prior art and can be administered orally, perorally, parenterally, intravenously, intraperitoneal^, intradermal^, intramuscularly, intranasally, buccally, rectally or locally, for example to the skin, the mucous membranes or into the eyes. The compounds exhibit analgesic properties and are particularly suitable for the treatment of acute, visceral, neuropathic or chronic pain (cf., e.g., WO 2004/043967 and WO 2008/040481 ).

Conventional analgesics are typically available as formulations providing immediate release or as formulations providing prolonged release. On the one hand, formulations providing immediate release upon oral administration have the advantage that they lead to a fast release of the analgesic in the gastrointestinal tract. As a result, a comparatively high dose of the analgesic is quickly absorbed leading to high plasma levels within a short period of time and resulting in a rapid onset of pain relief, i.e. analgesic action begins shortly after administration. This is particularly desirable in acute pain.

At the same time, however, a rapid reduction in the analgesic action is usually observed, because metabolization and/or excretion of the analgesic cause a decrease of its plasma levels. For that reason, formulations providing immediate release of analgesics typically need to be administered frequently, e.g. eight times per day. This is not only detrimental with respect to patient compliance but also may cause comparatively high peak plasma drug concentrations and high fluctuations between peak and trough plasma drug concentrations which in turn may deteriorate tolerability.

On the other hand, formulations providing prolonged release upon oral administration have the advantage that they need to be administered less frequently, typically once daily or twice daily. This improves patient compliance and also can reduce peak plasma drug concentrations and fluctuations between peak and trough plasma drug concentrations which in turn may improve tolerability.

At the same time, however, release of the analgesic in the gastrointestinal tract is prolonged. As a result, a comparatively low dose of the analgesic is quickly absorbed leading to low plasma levels and resulting in a retarded onset of pain relief, i.e. analgesic action begins quite a while after first administration.

Furthermore, as formulations providing prolonged release typically contain higher doses of the analgesics than formulations providing immediate release, they bear a higher risk of being misused. Older patients in particular frequently have difficulties in taking solid pharmaceutical dosage forms. To counter this problem, various apparatuses have been developed by means of which solid pharmaceutical dosage forms may be comminuted or pulverized ("tablet crushers"). Such apparatuses are used, for example, by the care staff in old people's homes. The pharmaceutical dosage forms are then administered to the people being cared for not as tablets etc. but rather as powder, for example to get round the difficulties involved in swallowing tablets. However, the comminution of pharmaceutical dosage forms with such apparatuses is problematic if the pharmaceutical dosage forms are prolonged release formulations. As a rule, comminution then results in destruction of the inner structure of the pharmaceutical dosage form, which is responsible for the prolonged release, so doing away with the prolonged-release action. Consequently, after administration, frequently all the physiologically active substance originally contained in the pharmaceutical dosage form is released in a relatively short time, whereby a comparatively very high plasma concentration of the substance is abruptly reached for a relatively short period (dose dumping). In this way, the original prolonged-release formulations become immediate-release formulations. Depending on the physiological activity of the substance, this may cause considerable side-effects however, and in extreme cases may even lead to the death of the patient (cf., e.g., J. E. Mitchell, Oral Pharmaceutical dosage forms That Should Not Be Crushed: 2000 Update, Hospital Pharmacy, 2000; H. Miller et al., To Crush or Not to Crush, Nursing 2000; R. Griffith et al., Tablet Crushing and the law: the implications for nursing; Prof. Nurse 2003). Intentional chewing of prolonged-release formulations may also lead to an overdose of the substance contained therein. Sometimes patients chew the pharmaceutical dosage forms deliberately, though often in ignorance of the type and purpose of a prolonged-release formulation, because they hope for a quicker effect.

Formulations providing a dual release mode, i.e. a combination of immediate release with prolonged release, are also known (cf., e.g., CM. Lopez et al., Compressed Matrix Core Tablet as a Quick/Slow Dual-Component Delivery System Containing Ibuprofen, AAPS PharmSciTech 2007; 8(3), E1-E8). However, these formulations typically rely upon immediate-release units and prolonged-release units that are locally separated from one another and therefore, such pharmaceutical dosage forms can only be prepared by specific and costly methods.

It is an object of the invention to provide pharmaceutical dosage forms containing 6'-Fluoro- (N-methyl- or N,N-dimethyl-)-4-phenyl-4',9'-dihydro-3'H-spiro[cyclohexane- 1 ,1'-pyrano[3,4,b]- indol]-4-amine which have advantages compared to the pharmaceutical dosage forms of the prior art. In particular, the pharmaceutical dosage forms should provide good bioavailability and rapid pain relief already after the first administration, but also should have a high tolerability, good compliance, and safety.

This object has been achieved by the subject-matter of the patent claims.

It has been surprisingly found that 6'-Fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4',9'- dihydro-3'H-spiro[cyclohexane-1 ,1'-pyrano[3,4,b]indol]-4-amine has a comparatively poor water solubility. Further, it has been surprisingly found that in spite of said poor water solubility, pharmaceutical dosage forms can be prepared which provide immediate release of 6'-Fluoro-(N-methyl- or N.N-dimethyl- -phenyl-^.Q'-dihydro-S'H-spirotcyclohexane-l ,1 '-py- rano[3,4,b]indol]-4-amine and provide good bioavailability. Still further, it has been surprisingly found that 6'-Fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4',9'-dihydro-3'l-l- spiro[cyclohexane-1 ,1 '-pyrano[3,4,b]indol]-4-amine has a relatively large pharmacokinetic half life time (t _{1 2} ) and thus, provides pharmacological activity for a comparatively extended period of time after administration.

Therefore, it has been surprisingly found that upon preferably oral administration of the pharmaceutical dosage form containing the pharmacologically active agent according to the invention, a rapid onset of pain relief can be achieved followed by a prolonged analgesic effect, although, or even if, the pharmaceutical dosage form provides immediate release. Therefore, the pharmaceutical dosage form according to the invention combines the advantageous properties of conventional formulations providing immediate release - rapid pain relief due to adequately high concentration of active ingredient just after administration of the pharmaceutical composition - with the advantageous properties of conventional formulations providing prolonged release - long-lasting analgesic action owing to an adequately high level of active ingredient over a prolonged time -, and at the same time even overcomes the drawbacks of said conventional formulations. By taking the pharmacologically active agent in the formulation according to the invention, the patient can effectively combat his pain acutely and, at the same time, treat if effectively over a prolonged period without further measures and merely by regular administration at 12 (or e.g., 24) hourly intervals.

It is particularly surprising that the pharmaceutical dosage form according to the invention not only allows the pharmacologically active agent to start flowing rapidly in the plasma when the pharmaceutical dosage form is first administered, leading to a rapid onset of pain relief in the patient owing to the immediate release, but at the same time ensures long-lasting therapeutic efficacy over a relatively long period (at least 12 hours). Therefore, the pain suffered by a patient can rapidly be alleviated when the pharmaceutical dosage form according to the invention is administered without the analgesic action quickly fading again.

The pharmaceutical dosage form according to the invention has good patient compliance and safety. Even if the pharmaceutical dosage form according to the invention is tampered with, e.g. by means of tablet crushers, dose dumping cannot occur - crushing the pharmaceutical dosage form does not further accelerate the immediate release profile.

Figure 1 shows the averaged numerical rating scale (NRS) values measured over a 24 hour period after administration of different single doses of the compound according to formula (I'D) (200, 400, 600 pg) compared to morphine and placebo in patients with acute postoperative pain following orthopedic surgery (bunionectomy).

The invention relates to a pharmaceutical dosage form containing a pharmacologically active agent according to general formula (I)

wherein R is -H or -CH ₃ , or a physiologically acceptable salt thereof; said pharmaceutical dosage form being for administration twice daily, once daily or less frequently.

The pharmacologically active agent according to general formula (I) can also be referred to as "6'-fluoro-N-methyl-4-phenyl-4',9'-dihydro-3'l-l-spiro[cyclo hexane-1 ,1 '-pyrano[3,4,b]indol]- 4-amine" when R is -H, and "6'-fluoro-N,N-dimethyl-4-phenyl-4',9'-dihydro-3'H-spiro- [cyclohexane-1 ,1 '-pyrano[3,4,b]indol]-4-amine" when R is -CH ₃ ; for the purpose of the specification, the pharmacologically active agent according to general formula (I) can also be referred to as "6'-fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4\9'-dihydro-3'H- spiro[cyclohexane-1 , 1 '-pyrano[3,4,b]indol]-4-amine".

In a preferred embodiment, the pharmacologically active agent according to general formula (I) has a stereochemistry according to general formula (Γ)

wherein R is -H or-CH ₃ , or a physiologically acceptable salt thereof. In another embodiment of the pharmaceutical dosage form according to the invention, the compound of formula (I) is selected from

in the form of the free base or a physiologically acceptable salt thereof.

The free base according to general formula (I'a) can be systematically referred to as "1 ,1 -(3- methylamino-3-phenylpentamethylene)-6-fluoro-1 ,3,4,9-tetrahydropyrano[3,4-b]indole (trans)" or as "(I r^ -e'-fluoro-N-methyl^-phenyl^'.Q'-dihydro-S'H-spirotcyclohexa ne-l .l '- pyrano[3,4,b]indol]-4-amine", respectively.

The free base according to general formula (I'b) can be systematically referred to as "1 ,1-(3- dimethylamino-3-phenylpentamethylene)-6-fluoro-1 ,3,4,9-tetrahydropyrano[3,4-b]indole (trans)" or as "(I r^rJ-S'-fluoro-N.N-dimethyl^-phenyl^'.Q'-dihydro-S'H-spiroIc yclohexane- 1 ,1 '-pyrano[3,4,b]indol]-4-amine", respectively.

The definition of the pharmacologically active agent according to general formula (I) as used herein includes 6'-fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4\9'-dihydro-3'H-spiro- [cyclohexane-1 ,1 '-pyrano[3,4,b]indol]-4-amine, derivatives thereof and stereoisomers thereof in any possible form, thereby particularly including solvates and polymorphs, salts, in particular acid addition salts and corresponding solvates and polymorphs.

In a preferred embodiment, the pharmacologically active agent according to general formula (I) is present as the single diastereomer according to general formula ( ).

In another preferred embodiment the pharmacologically active agent according to general formula (I) is present as mixture of diastereomers. Such a mixture may contain the diastereomers in any ratio. A diastereomeric mixture could, for example, contain the diastereomers in a ratio of 60±5:40±5, 70±5:30±5, 80+5:20+5 or 90±5:10±5. Preferably, the pharmaceutical dosage form according to the invention contains the diastereomer according to general formula (Γ) in a diastereomeric excess (de) of at least 50%de, more preferably at least 60%de, still more preferably at least 70%de, yet more preferably at least 80%de, even more preferably at least 90%de, most preferably at least 95%de, and in particular at least 98%de, with respect to the other diastereomer (i.e. trans vs. cis and anti vs. syn, respectively).

6'-Fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4',9'-dihydro-3'l-l-spiro[cyclohexan e-1 ,1'-py- rano[3,4,b]indol]-4-amine may be present in the pharmaceutical dosage form according to the invention in form of the free base or in form of an acid addition salt, whereby any suitable acid capable of forming such an addition salt may be used.

The conversion of 6'-Fluoro-(N-methyl- or N,N-dimethyl-)-4-phenyl-4',9'-dihydro-3'H-spiro- [cyclohexane-1 ,1'-pyrano[3,4,b]indol]-4-amine into a corresponding addition salt, for example, via reaction with a suitable acid may be effected in a manner well known to those skilled in the art. Suitable acids include but are not limited to hydrochloric acid, hydrobromic acid, sulfuric acid, methanesulfonic acid, formic acid, acetic acid, oxalic acid, succinic acid, tartaric acid, mandelic acid, fumaric acid, lactic acid, citric acid, glutamic acid and/or aspartic acid. Salt formation is preferably effected in a solvent, for example, diethyl ether, diisopropyl ether, alkyl acetates, acetone and/or 2-butanone. Moreover, trimethylchlorosilane in aqueous solution is also suitable for the preparation of hydrochlorides.

The pharmacologically active agent according to general formula (I) is contained in the pharmaceutical dosage form in a therapeutically effective amount. The amount that constitutes a therapeutically effective amount varies according to the compound, the condition being treated, the severity of said condition, the patient being treated, and whether the pharmaceutical dosage form is designed for an immediate or retarded release.

In a preferred embodiment, the content of the pharmacologically active agent according to the general formula (I) in the pharmaceutical dosage form according to the invention is at most 95 wt.-%, more preferably at most 50 wt.-%, yet more preferably at most 25 wt.-%, still more preferably at most 10 wt.-%, even more preferably at most 5 wt.-%, most preferably at most 1.0 wt.-%, and in particular at most 0.5 wt.-%.

In another preferred embodiment, the content of the pharmacologically active agent according to the general formula (I) in the pharmaceutical dosage form according to the invention is at least 0.001 wt.-%, more preferably at least 0.005 wt.-%, yet more preferably at least 0.01 wt.-%, still more preferably at least 0.05 wt.-%, even more preferably at least 0.1 wt.-%, most preferably at least 0.5 wt.-%, and in particular at least 1.0 wt.-%. In still another preferred embodiment, the content of the pharmacologically active agent according to the general formula (I) in the pharmaceutical dosage form according to the invention is within the range of 0.320±0.315 wt.-%, more preferably 0.320±0.310 wt.-%, still more preferably 0.320±0.305 wt.-%, yet more preferably 0.320±0.300 wt.-%, even more preferably 0.320±0.295 wt.-%, most preferably 0.320±0.290 wt.-%, and in particular 0.320±0.285 wt.-%.

In yet another preferred embodiment, the content of the pharmacologically active agent according to the general formula (I) in the pharmaceutical dosage form according to the invention is within the range of 0.040±0.035 wt.-%, more preferably 0.040±0.030 wt.-%, still more preferably 0.040±0.025 wt.-%, yet more preferably 0.040±0.020 wt.-%, even more preferably 0.040±0.015 wt.-%, most preferably 0.040±0.010 wt.-%, and in particular 0.040±0.005 wt.-%.

In another preferred embodiment, the content of the pharmacologically active agent according to the general formula (I) in the pharmaceutical dosage form according to the invention is within the range of 0.6±0.35 wt.-%, more preferably 0.6±0.30 wt.-%, still more preferably 0.6±0.25 wt.-%, yet more preferably 0.6±0.20 wt.-%, even more preferably 0.6±0.15 wt.-%, most preferably 0.6±0.10 wt.-%, and in particular 0.6±0.05 wt.-%.

Unless explicitly stated otherwise, in the meaning of the present invention the indication "wt.- %" shall mean weight of the respective ingredient per total weight of the pharmaceutical dosage form. In case that the pharmaceutical dosage form is film coated or encapsulated by an encapsulating medium which does not contain any amount of the pharmacologically active agent according to the general formula (I) and surrounds a core that in turn contains the total amount of the pharmacologically active agent according to the general formula (I), the indication "wt.-%" shall mean weight of the respective ingredient per total weight of the composition forming said core.

When the pharmaceutical dosage form is encapsulated or film coated, the pharmacologically active agent according to general formula (I) is preferably homogeneously distributed in the core of the pharmaceutical dosage form. Preferably, the encapsulating medium or film coating does not contain any pharmacologically active agent according to general formula (I). The dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 0.1 pg to 5000 pg, more preferably in the range of 0.1 pg to 1000 pg, and most preferably in the range of 1.0 pg to 100 pg or in the range of 30 pg to 600 pg.

In a preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 25±20 pg, more preferably 25±15 pg, still more preferably 25±10 pg, and most preferably 25±5 pg.

In another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 40±35 pg, more preferably 40±30 pg, still more preferably 40±25 pg, yet more preferably 40±20 pg, even more preferably 40±15 pg, most preferably 40±10 pg, and in particular 40±5 M9-

In still another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 50±35 pg, more preferably 50±30 pg, still more preferably 50±25 pg, yet more preferably 50±20 pg, even more preferably 50±15 pg, most preferably 50±10 pg, and in particular 50±5 M9-

In yet another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 60±35 pg, more preferably 60±30 pg, still more preferably 60±25 pg, yet more preferably 60±20 pg, even more preferably 60±15 pg, most preferably 60±10 pg, and in particular 60±5 M9-

In another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 100±90 pg, more preferably 100±80 pg, still more preferably 100±60 pg, yet more preferably 100±40 pg, even more preferably 100±20 pg, most preferably 100±10 pg, and in particular 100±5 pg.

In still another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 200±175 pg, more preferably 200±150 pg, still more preferably 200±125 pg, yet more preferably 200±100 pg, even more preferably 200±75 pg, most preferably 200±50 pg, and in particular 200±25 pg. In yet another preferred embodiment, the content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form is within the range of 400±350 pg, more preferably 400±300 pg, still more preferably 400±250 pg, yet more preferably 400±200 pg, even more preferably 400±150 pg, most preferably 400±100 pg, and in particular 400±50 pg.

In a preferred embodiment the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 50 pg to 3000 pg, more preferably in the range of 100 pg to 1000 pg, even more preferably in the range of 300 pg to 500 pg, and most preferably in the range of 350 pg to 450 pg.

In another preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 200 pg to 400 pg, and in particular in the range of 250 pg to 350 pg.

For the purpose of the specification, the wording "being for use in the treatment of pain" is equivalent with "being adapted for use in the treatment of pain".

In a preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 200 pg to 400 pg, and in particular in the range of 250 pg to 350 pg.

In a preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 250 pg to 450 pg, and in particular in the range of 300 pg to 400 pg.

In another preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 300 pg to 500 pg, and in particular in the range of 350 pg to 450 pg. In yet another preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 350 pg to 550 pg, and in particular in the range of 400 pg to 500 pg.

In even another preferred embodiment, the pharmaceutical dosage form is for use in the treatment of acute pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 400 pg to 600 pg, and in particular in the range of 450 pg to 550 pg.

In another preferred embodiment the pharmaceutical dosage form is for use in the treatment of chronic pain, where the dose of the pharmacologically active agent according to general formula (I) preferably is in the range of 0.1 pg to 500 pg, more preferably in the range of 1 pg to 250 pg, even more preferably in the range of 5 pg to 100 pg, and most preferably in the range of 10 pg to 50 pg.

In a preferred embodiment, the pharmaceutical dosage form according to the invention is for oral administration, i.e. the pharmaceutical dosage form is adapted for oral administration. Suitable alternative pathways of administration of the pharmaceutical dosage form according to the invention include but are not limited to vaginal and rectal administration.

The pharmaceutical dosage form according to the invention is for administration twice daily, once daily or less frequently, i.e. the pharmaceutical dosage form is adapted for administration twice daily, once daily or less frequently.

In a preferred embodiment, the pharmaceutical dosage form according to the invention is for administration twice daily.

For the purpose of the specification, "administration twice daily" (bid) preferably means that the pharmaceutical dosage form is adapted for being administered according to a regimen comprising the administration of a first pharmaceutical dosage form according to the invention and the subsequent administration of a second pharmaceutical dosage form according to the invention, wherein both, the first and the second pharmaceutical dosage form are administered during a time interval of about 24 hours, but wherein the second pharmaceutical dosage form is administered not earlier than 6 hours, preferably not earlier than 8 hours, more preferably not earlier than 10 hours and in particular, about 12 hours after the first pharmaceutical dosage form has been administered. In another preferred embodiment, the pharmaceutical dosage form according to the invention is for administration once daily.

For the purpose of the specification, "administration once daily" (sid) preferably means that the pharmaceutical dosage form is adapted for being administered according to a regimen comprising the administration of a first pharmaceutical dosage form according to the invention and the subsequent administration of a second pharmaceutical dosage form according to the invention, wherein both, the first and the second pharmaceutical dosage form are administered during a time interval of about 48 hours, but wherein the second pharmaceutical dosage form is administered not earlier than 18 hours, preferably not earlier than 20 hours, more preferably not earlier than 22 hours and in particular, about 24 hours after the first pharmaceutical dosage form has been administered.

In another preferred embodiment, the pharmaceutical dosage form according to the invention is for administration once daily or less frequently.

In another preferred embodiment, the pharmaceutical dosage form according to the invention is for administration less frequently than once daily, preferably thrice during four days (3/4), twice during three days (2/3), thrice during five days (3/5), once during two days (1/2), thrice in a week (3/7), twice during five days (2/5), once during three days (1/3), twice in a week (2/7), once during four days (1/4), once during five days (1/5), once during six days (1/6), or once in a week (1/7). According to this embodiment, administration once during two days (1/2) is particularly preferred.

A skilled person is fully aware that administration regimens "twice daily, once daily, or less frequently" may be realized by administering a single pharmaceutical dosage form containing the full amount of the pharmacologically active agent according to general formula (I) to be administered at a particular point in time or, alternatively, administering a multitude of dose units, i.e. two, three or more dose units, the sum of which multitude of dose units containing the full amount of the pharmacologically active agent according to general formula (I) to be administered at said particular point in time, where the individual dose units are for simultaneous administration or administration within a short period of time, e.g. within 5, 10 or 15 minutes.

Preferably, the pharmaceutical dosage form according to the invention provides immediate release of the pharmacologically active agent according to general formula (I). Preferably, the pharmaceutical dosage form is specifically designed to provide immediate release of the pharmacologically active agent according to general formula (I) in vitro in accordance with Ph. Eur. When the pharmaceutical dosage form is coated, e.g., with a coating that is soluble in gastric juice, the release kinetic is preferably monitored after such coating has been dissolved.

For the purpose of specification, the term "immediate release" refers to any release profile that fulfills at least one, preferably both, of the following requirements. First, the pharmaceutical dosage form disintegrates in 10 minutes or less following exposure to a disintegrating medium. Methods to determine the disintegration time are known to a person skilled in the art. For instance, they can be determined according to the USP XXIV disintegration test procedure, using, for example, an Erweka ZT-71 disintegration tester. Second, the pharmaceutical dosage form releases at least 70 wt.-% of the drug within 15 minutes following exposure to a dissolution medium. Preferably, the in vitro release properties of the pharmaceutical dosage form according to the invention are determined according to the paddle method with sinker at 50, 75 or 100 rpm, preferably under in vitro conditions at 37 ±0.5 °C in 900 mL artificial gastric juice at pH 1.2, or under the same conditions in non-artificial gastric juice.

In a preferred embodiment, the pharmaceutical dosage form releases under in vitro conditions in 900 mL artificial gastric juice at pH 1.2 and 37 ±0.5 °C after 30 minutes according to the paddle method with sinker at 100 rpm at least 50 wt.-%, more preferably at least 60 wt.-%, still more preferably at least 70 wt.-%, yet more preferably at least 80 wt.-%, most preferably at least 90 wt.-%, and in particular at least 95 wt.-% of the pharmacologically active agent according to general formula (I), based on the total amount of the pharmacologically active agent according to general formula (I) originally contained in the pharmaceutical dosage form.

The pharmaceutical dosage form according to the invention exhibits excellent shelf-life and storage stability, i.e. neither the chemical composition, nor the physical characteristics, nor the dissolution profile of the pharmaceutical dosage form are altered significantly upon storage.

In a preferred embodiment, the pharmaceutical dosage form according to the invention provides sufficient stability to the pharmacologically active agent according to general formula (I) contained therein, so that after storage of the pharmaceutical dosage form at 40±2°C at 75% RH ±5% for a minimum time period of 6 weeks, preferably 3 months, the concentrations of undesirable degradants and impurities, respectively, preferably resulting from a degradation or decomposition of the pharmacologically active agent according to general formula (I) as such, is at most 1.0 wt.-%, more preferably at most 0.8 wt.-%, still more preferably at most 0.6 wt.-%, yet more preferably at most 0.4 wt.-%, even more preferably at most 0.2 wt.-%, most preferably at most 0.1 wt.-%, and in particular at most 0.05 wt.-%, relative to the original content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form, i.e. its content before subjecting the pharmaceutical dosage form to storage.

It has been found that the pharmacologically active agent according to general formula (I) may be decomposed by elimination of the group -NRCH ₃ thereby yielding 6'-fluoro-4-phenyl- 4',9'-dihydro-3'H-spiro[cyclohex-3-ene-1 ,1'-pyrano[3,4-b]indole] which appears to be pharmacologically inactive. Preferably, after storage of the pharmaceutical dosage form at 40±2°C and 75% RH ±5%, or at 25±2°C and 60% RH ±5%, for a minimum time period of 6 weeks, preferably 3 months, the concentration of 6'-fluoro-4-phenyl-4\9'-dihydro-3'H-spiro[cyclohex- 3-ene-1 ,1 '-pyrano[3,4-b]indole] is at most 1.0 wt.-%, more preferably at most 0.8 wt.-%, still more preferably at most 0.6 wt.-%, yet more preferably at most 0.4 wt.-%, even more preferably at most 0.2 wt.-%, most preferably at most 0.1 wt.-%, and in particular at most 0.05 wt.-%, relative to the original content of the pharmacologically active agent according to general formula (I) in the pharmaceutical dosage form, i.e. its content before subjecting the pharmaceutical dosage form to storage.

A generally accepted accelerated test for the determination of a drug's stability according to ICH and FDA guidelines relates to the storage of a pharmaceutical formulation containing the drug (e.g., in its container and packaging). According to the ICH guidelines, a so-called accelerated storage testing should be conducted for pharmaceutical formulations at 40±2°C at 75% RH ±5% for a minimum time period of 6 months. Additionally, a so-called long-term storage testing should be conducted for pharmaceutical formulations at 25±2°C at not less than 60% RH ±5% for a minimum time period of 12 months. In case that all criteria have been met for the accelerated storage testing and long-term storage testing conditions during the 6-months period, the long-time storage testing may be shortened to 6 months and the corresponding data doubled to obtain estimated data for the 12-month period.

During the storage, samples of the pharmaceutical formulation are withdrawn at specified time intervals and analyzed in terms of their drug content, presence of impurities, their release profile and if applicable other parameters. According to the ICH guidelines, in all samples the purity of the drug should be≥ 98%, the drug content should be 95-105% (FDA guideline: 90-110%). Furthermore, the pharmaceutical formulation should release >80% of the drug within 30 minutes.

In case of tablets and capsules that contain less than 50 mg of a drug, a content uniformity test should additionally be conducted for 10 randomly chosen dosage forms. The pharmaceutical formulation complies if none individual content is outside the limits of 85% to 115 % of the average content. In case that an individual content is outside these limits, another 30 capsules have to be analyzed. The preparation fails to comply with the test if more than 3 individual contents are outside the limits of 85 to 115 % of the average content or if one or more individual contents are outside the limits of 75 % to 125 % of the average content.

In a preferred embodiment, after storage of the pharmaceutical dosage form for 6 months under long-term storage conditions (25°C and 60% relative humidity) in a sealed glass container, the degradation of the pharmacologically active agent according to general formula (I) does not exceed 2.0%, more preferably 1.5%, still more preferably 1.0%, and most preferably 0.5%.

In another preferred embodiment, after storage of the pharmaceutical dosage form for 6 months under accelerated storage conditions (40°C and 75% relative humidity) in a sealed glass container, the degradation of the pharmacologically active agent according to general formula (I) does not exceed 4%, more preferably 3%, still more preferably 2%, yet more preferably 1%, and most preferably 0.5%.

Preferably, after storage of the pharmaceutical dosage form for 6 months under long-term storage conditions (25°C and 60% relative humidity), the pharmaceutical dosage form releases under in vitro conditions in 900 mL artificial gastric juice at pH 1.2 and 37 ±0.5 °C after 30 minutes according to the paddle method with sinker at 100 rpm at least 50 wt.-%, more preferably at least 60 wt.-%, still more preferably at least 70 wt.-%, and most preferably at least 80 wt.-% of the pharmacologically active agent according to general formula (I), based on the total amount of the pharmacologically active agent according to general formula (I) originally contained in the pharmaceutical dosage form.

Preferably, after storage of the pharmaceutical dosage form for 6 months under accelerated storage conditions (40°C and 75% relative humidity), the pharmaceutical dosage form releases under in vitro conditions in 900 mL artificial gastric juice at pH 1.2 and 37 ±0.5 °C after 30 minutes according to the paddle method with sinker at 100 rpm at least 50 wt.-%, more preferably at least 60 wt.-%, still more preferably at least 70 wt.-%, and most preferably at least 80 wt.-% of the pharmacologically active agent according to general formula (I), based on the total amount of the pharmacologically active agent according to general formula (I) originally contained in the pharmaceutical dosage form.

The absorption properties of a pharmacologically active agent administered by a pharmaceutical dosage form can be described by the pharmacokinetic parameters C _ma x, t _max and AUCo-t- The determination of C _max and t _max , as well as the calculation of an AUC are well known to a person skilled in the art and described, for example, in Bauer, Fromming, Fiihrer, "Lehrbuch der Pharmazeutischen Technologie," 6th Edition (1999), and in Shargel, Wu- Pong, Yu, "Applied Biopharmaceuticals & Pharmacokinetics," 5 ^th Edition (2005).

There is experimental evidence indicating that AUCo-t and C _max of the pharmacologically active agent according to general formula (I) are proportional to the dose.

For the purpose of the specification, C _max is the highest plasma concentration of the pharmacologically active agent reached after single administration of the pharmaceutical dosage form.

For the purpose of the specification, t _max is the time needed in order to reach C _max .

For the purpose of the specification, AUC _0-t is the area under the curve after single administration to the time t of the last sample that contained an analytically quantifiable concentration of the pharmacologically active agent.

For the purpose of the specification, AUC _0- 72h is the area under the curve baseline after single administration to 72 hours thereafter.

Preferably, the ratio C _max / dose is within the range of from 0.01 to 3.00 m ^"3 , yet more preferably within the range of from 0.02 to 2.50 m ^"3 , more preferably within the range of from 0.04 to 2.00 m ^"3 , and most preferably within the range of from 0.06 to 1.69 m ^"3 . In a preferred embodiment, the ratio C _max / dose is within the range of 0.40±0.35 m ^"3 , more preferably 0.40±0.30 m ^"3 , still more preferably 0.40±0.25 m ^"3 , yet more preferably 0.40±0.20 m ^"3 , even more preferably 0.40±0.15 m ^"3 , most preferably 0.40±0.10 m ^"3 , and in particular 0.40±0.05 m ^{" 3} . In another preferred embodiment, the ratio C _max / dose is within the range of 0.80±0.70 m ^"3 , more preferably 0.80±0.60 m ^"3 , still more preferably 0.80±0.50 m ^"3 , yet more preferably 0.80±0.40 m ^"3 , even more preferably 0.80±0.30 m ^"3 , most preferably 0.80±0.20 m ^"3 , and in particular 0.80+0.10 rrf ³ . In still another preferred embodiment, the ratio C _max / dose is within the range of 1.20±1.05 m ^"3 , more preferably 1.20±0.90 m ^"3 , still more preferably 1.20±0.75 m ^{" 3} , yet more preferably 1.20±0.60 m ^~3 , even more preferably 1.20±0.45 m ^"3 , most preferably 1.20±0.30 m ^"3 , and in particular 1.20±0.15 m ^"3 .

Preferably, t _max is within the range of from 15 minutes to 24 h, still more preferably within the range of from 20 minutes to 20 h, yet more preferably within the range of from 0.5 to 16 h, most preferably within the range of from 1 to 12 h, and in particular within the range of from 2 to 10 h. In a preferred embodiment, is within the range of 4±3.5 h, more preferably 4±3 h, still more preferably 4±2.5 h, yet more preferably 4±2 h, even more preferably 4±1.5 h, most preferably 4±1 h, and in particular 4±0.5 h. In another preferred embodiment, t _max is within the range of 8±7 h, more preferably 8±6 h, still more preferably 8±5 h, yet more preferably 8±4 h, even more preferably 8±3 h, most preferably 8±2 h, and in particular 8±1 h. In still another preferred embodiment, t _max is within the range of 12±11 h, more preferably 12±9 h, still more preferably 12±7 h, yet more preferably 12±5 h, even more preferably 12±3 h, most preferably 12±2 h, and in particular 12±1 h.

Preferably, the ratio AUCo- _t / dose is within the range from 0.3 to 20 h/m ³ , more preferably within the range of from 0.4 to 18 h/m ³ , still more preferably within the range of from 0.5 to 16.5 h/m ³ and most preferably within the range of from 0.55 to 12.5 h/m ³ . In a preferred embodiment, the ratio AUC _0- t / dose is within the range of 3±2.5 h/m ³ , more preferably 3±2 h/m ³ , still more preferably 3±1.5 h/m ³ , yet more preferably 3±1 h/m ³ , even more preferably 3±0.75 h/m ³ , most preferably 3±0.5 h/m ³ , and in particular 3±0.25 h/m ³ . In another preferred embodiment, the ratio AUC _0-t / dose is within the range of 6±5 h/m ³ , more preferably 6±4 h/m ³ , still more preferably 6±3 h/m ³ , yet more preferably 6±2 h/m ³ , even more preferably 6±1.5 h/m ³ , most preferably 6±1 h/m ³ , and in particular 6±0.5 h/m ³ . In still another preferred embodiment, the ratio AUC _0- t / dose is within the range of 9±8 h/m ³ , more preferably 9±7 h/m ³ , still more preferably 9±5 h/m ³ , yet more preferably 9±4 h/m ³ , even more preferably 9±3 h/m ³ , most preferably 9±2 h/m ³ , and in particular 9±1 h/m ³ .

In a preferred embodiment, the pharmaceutical dosage form according to the invention is monolithic.

In another preferred embodiment, the pharmaceutical dosage form according to the invention comprises a core that is surrounded by a coating or by an encapsulating material. In a preferred embodiment, the core is liquid and the pharmacologically active agent according to general formula (I) is dispersed, preferably dissolved in the liquid. Preferably, the pharmaceutical dosage form according to the invention provides the pharmacologically active agent according to general formula (I) in form of self-(micro) emulsifying drug delivery systems, solid solutions, nanoparticles, cyclodextrin complexes, liposomes, micelles, micronized and/or amorphous states.

In general terms, the options for formulation of poorly water-soluble drugs include crystalline solid, amorphous and lipid formulations.

The dissolution rate of the pharmacologically active agent from crystalline formulations can be increased by particle size reduction, thereby increasing the surface area for dissolution, e.g. by conventional micronisation of the pharmacologically active agent to particle sizes of about 2-5 μητι. In some cases, this is not sufficient and nanocrystal technology is applied. Nanocrystals show a particle size of 100-250 nm, which can be obtained by ball-milling or by dense gas or supercritical fluid technology.

Solid solutions provide and sustain the pharmacologically active agent in an amorphous state immobilized in a polymer. Amorphous solutions may contain surfactants and polymers, thereby providing surface-activity during dispersion upon contact with water. Solid solutions can be formed using a variety of technologies such as spray drying and melt extrusion.

Lipid formulations exhibiting different characteristics can be used to disperse and form micellar solutions, including simple solutions and self-emulsifying drug delivery systems (SEDDS). Depending on the excipients, some require digestion (e. g. simple oily liquids), others can easily be absorbed without digestion. Lipid formulations have been classified according to the lipid formulation classification system (LFCS) as follows:

Excipients in formulation Content of formulation (wt.-%)

Type I Type II Type MA Type NIB Type IV

Oil: triglycerides or mixed mono- and diglycerides 100 40-80 40-80 < 20 -

Water-insoluble surfactants (HLB < 12) - 20-60 - - 0-20

Water-soluble surfactants (HLB > 12) - - 20-40 20-50 30-80

Hydrophilic co-solvent - - 0-40 20-50 0-50

Another option is the formation of cyclodextrin complexes, in which the pharmacologically active agent is located in the cavity of the cyclodextrin and is thereby molecularly present in a more soluble form in presence of aqueous media. The success of the fitting strongly depends on the quality of the cyclodextrins as well as on the physicochemical properties and size of the pharmacologically active agent.

In a preferred embodiment, the pharmaceutical dosage form according to the invention can be regarded as a self emulsifying drug delivery system (SEDDS).

For that purpose, the pharmacologically active agent according to general formula (I) is preferably embedded in a self-emulsifying formulation. A so called self emulsifying drug delivery system (SEDDS) is a drug delivery system that uses an emulsion achieved by chemical rather than mechanical means. That is, by an intrinsic property of the drug formulation, rather than by special mixing and handling. Said formulation dilutes in aqueous media and results in an emulsion. In case that the average droplet size is smaller than or equal to 50 nm, the self emulsifying drug delivery system (SEDDS) is referred to as self- micro emulsifying drug delivery system (SMEDDS). According to the lipid formulation classification system, these formulations are typically assigned to the group of type III formulations.

A preferred sub-group of SEDDSs are self-emulsifying oily formulations (SEOF). SEOFs typically comprise a natural or synthetic oil, surfactant and hydrophilic solvent and sometimes co-solvents. The principal characteristic of SEOFs is their ability to form fine oil-in-water emulsions or micro emulsions upon mild agitation following dilution by aqueous phases. These formulations can disperse in the gastrointestinal lumen to form micro emulsions or fine emulsions, upon dilution with gastrointestinal fluids.

In another preferred embodiment, the pharmaceutical dosage form contains the pharmacologically active agent according to general formula (I) in form of a solid solution, i.e. molecularly dispersed in a solid matrix. The solid solution preferably comprises the pharmacologically active agent according to general formula (I) in a molecular disperse form and an amorphous polymer matrix having a comparatively large specific surface. The pharmacologically active agent according to general formula (I) is preferably present in a molecular disperse form, i.e. the compound is truly solved and evenly spread in the solidified solution. The particle size of the compound is neither microcrystalline nor fine crystalline. The typical particle size is preferably from 0.1 - 1 pm.

In still another preferred embodiment, the pharmacologically active agent according to general formula (I) is provided by means of a nanotechnological formulation with an average size of the nanoparticles of preferably less than 1 pm. In a preferred embodiment, the pharmacologically active agent according to general formula (I) is provided in nanonized from. In another preferred embodiment, the pharmacologically active agent according to general formula (I) is blended with nanoparticles, preferably selected from organic nanoparticles and inorganic nanoparticles, and thus adsorbed to the surface of said particles.

Organic nanoparticles preferably contain small proteins which are present as a cluster or an agglomerate of small proteins, oligopeptides or lipids.

Inorganic nanoparticles preferably contain crystalline silicates. These silicates are from mineral origin or artificial silicates like metallosilicates (e.g. zeolites). In a preferred embodiment, the nanoparticles are modified in a way that they bear an electrostatic charge. The nanoparticles are preferably ultra finely grounded silicates and the pharmacologically active agent according to general formula (I) is preferably bounded to the micro porous surface of the nanoparticles.

The formation of nanoparticles is known to a person skilled in the art. One method is to produce colloidal nanoparticles as carriers for oral drug release by spraying the pharmacologically active agent according to general formula (I) under pressure at a defined temperature, together with a suitable carrier material like protamine, through jets, which are equipped with perforated strainers, into strongly cooled towers. The result of the fast cooling is an amorphous phase consisting of nanoparticles. Another method is to blend the pharmacologically active agent according to general formula (I) with suitable macromolecules in solution. By adding hydrophobic compounds, solvent molecules are removed from the solution and desolvation occurs. For this reason the formation of very tiny particles takes place wherein the pharmacologically active agent according to general formula (I) is integrated. For a hardening of the formed nanoparticles a crosslinker may be added to the solution.

To produce for example a solid lipid nanoparticle the method of high-pressure- homogenization and subsequent spray-cooling can be used. Preferably, the pharmacologically active agent according to general formula (I) is dissolved in a suitable solvent or in form of sub-micro particles. If applicable, a lipid vehicle and a surfactant may be added to the solution. Finally fine filler materials as outer phase as well as glidants and further surfactants may be added to fill the obtained formulation into e.g. capsules such as hard gelatin capsules. In yet another preferred embodiment, the pharmacologically active agent according to general formula (I) are provided as cyclodextrin (inclusion) complexes.

Cyclodextrins are composed of sugar molecules forming a ring and typically comprising 5 or more a-D-glycopyranoside units which are linked via the 1-4 position. The typical number of connected sugar monomers ranges from 6 to 8 units. A six membered sugar ring molecule is called a-cyclodextrin. A seven membered sugar ring molecule is called β-cyclodextrin and an eight membered sugar ring molecule is called γ-cyclodextrin. The shape of these compounds is a toroid with the larger and the smaller openings exposed to the solvent. Due to this formation the inner part of the toroid is not hydrophobic, but considerably less hydrophilic than the aqueous environment and thus able to host hydrophobic molecules. The outer part of the toroid is sufficiently hydrophilic to render cyclodextrins water solubility.

The inclusion of the pharmacologically active ingredient according to general formula (I) in cyclodextrins greatly modifies the physical and chemical properties. In most cases the mechanism of controlled degradation of such complexes and resultant drug release is based on pH change of aqueous solutions, leading to the cleavage of hydrogen or ionic bonds between the cyclodextrins and the included molecules. Alternative means for the disruption of the complexes take advantage of heating or action of enzymes able to cleave a-1-4 linkages between a-D-glycopyranosides.

In another preferred embodiment, the pharmacologically active agent according to general formula (I) is provided in form of liposomes. A liposome is preferably composed of phospholipids and is preferably of spherical shape. The shell of this shape is preferably a lamellar or bilayer structure. Another type of phospholipids arrangement is a monolayer.

Phospholipids comprise molecules with an amphiphilic character i.e. the molecules have a hydrophobic (lipophilic) and a hydrophilic (lipophobic) part. In the presence of water, the hydrophilic part is attracted to the water and forms a surface facing to the water, while the hydrophobic part is repelled by the water and forms a surface away from the water. Hence the amphiphilic molecules arrange themselves in one of the mentioned types.

The bilayer structures preferably arrange in a spherical shape wherein the inner part is filled with an aqueous solution. This type is called "liposome". The hydrophobic parts of the molecules face each other in the middle of the layer and the hydrophilic parts of the molecules face the water molecules outside of the liposome. The aqueous solution inside the liposome is the same as it is outside of the liposome. Ingredients solved in this aqueous solution, e.g. the pharmacologically active agents according to general formula (I), are in this way inside of the liposome. A typical diameter of the liposomes is between 25 nm and 1 pm. The smaller ones (25 nm - 200 nm) are made of one single bilayer while the bigger ones (200 nm - 1 pm) comprise more bilayer shells on the top of each other.

The monolayer structures also arrange in spherical shapes. Due to the amphiphilic character of the molecules and the spherical shape of the monolayer structures, the inner part of the spherical structures is filled with/formed by the hydrophobic parts of the molecules. These types are called micelles. There is no solvent inside the structure. In a preferred embodiment, the inner parts of the micelles contain the pharmacologically active agents according to general formula (I).

In another preferred embodiment the pharmacologically active agent according to general formula (I) is provided in a micronized state. By means of micronization technique particles of the pharmacologically active agent according to general formula (I) with a diameter in nanometer scale can be prepared. Said particles have a large surface to volume ratio.

Milling and grinding is a useful method to obtain particles in nanometer scale. Sophisticated techniques for the micronization include RESS (rapid expansion of supercritical solutions), SAS (supercritical anti solvent) and the PGSS (particles from gas saturated solutions).

The RESS method uses a supercritical fluid wherein the pharmacologically active agent according to general formula (I) is dissolved under high pressure and temperature thereby yielding a homogenous supercritical phase. After expanding the solution through a nozzle, small particles are formed. Due to the expansion at the end of the nozzle the solved pharmacologically active agent according to general formula (I) precipitates as crystals and encloses small amounts of the solvent. The solvent changes from the supercritical fluid state to the normal state, preferred the gas phase, and breaks the crystals from inside-out. In this way and due to the fact that the crystals collide with each other, particles with a diameter in nanometer scale are formed.

In the SAS method the pharmacologically active agent according to general formula (I) is dissolved in a preferably organic solvent. A supercritical fluid is added to the solution under pressure and thus forced to also dissolve in the solvent. In consequence, the volume of the complete system is increased and the solubility of the pharmacologically active agent according to general formula (I) is decreased. Due to its decreased solubility, the compound according to general formula (I) precipitates and forms particles having a small diameter. The PGSS method is similar to the SAS method. Here, the pharmacologically active agent according to general formula (I) is melted and a supercritical fluid is dissolved in the melt. Due to the expansion through a nozzle, the pharmacologically active agent according to general formula (I) precipitates and forms particles in a nanometer scale.

In a preferred embodiment, the pharmaceutical dosage form according to the invention contains

- a non-ionic surfactant (e.g. Cremophor ^® EL, Cremophor ^® RH 40, Cremophor ^® RH 60, d- alpha-tocopherol polyethylene glycol 1000 succinate, polysorbate 20, polysorbate 80, Solutol ^® HS 15, sorbitan monooleate, poloxamer 407, Labrafil ^® M-1944CS, Labrafil ^® M- 2125CS, Labrasol ^® , Gelucire ^® 44/14, Softigen ^® 767, and mono- and di-fatty acid esters of PEG 300, 400 or 1750); and/or

- an anionic surfactant such as sodium lauryl sulfate (sodium dodecyl sulfate, e.g.

Texapon ^® K12), sodium cetyl sulfate (e.g. Lanette E ^® ), sodium cetylstearyl sulfate, sodium stearyl sulfate, sodium dioctylsulfosuccinate (docusate sodium); and/or

- a water insoluble lipid (e.g. castor oil, corn oil cottonseed oil, olive oil, peanut oil, peppermint oil, safflower oil, sesame oil, soybean oil, hydrogenated vegetable oils, hydrogenated soybean oil, and medium chain triglycerides of coconut oil and palm seed oil); and/or

- an organic liquid/semi-solid (e.g. beeswax, d-alpha-tocopherol, oleic acid, medium chain mono- and diglycerides); and/or

- a cyclodextrin (e.g. alpha-cyclodextrin, beta-cyclodextrin, hydroxypropyl-beta-cyclo- dextrin, and sulfobutylether-beta-cyclodextrin); and/or

- a phospholipid (e.g. hydrogenated soy phosphatidylcholine, distearoylphosphatidyl- glycerol, L-alpha-dimyristoylphosphatidylcholine, and L-alpha-dimyristoylphosphatidyl- glycerol).

Preferably, the pharmacologically active agent according to general formula (I) is molecularly dispersed in a matrix.

In a preferred embodiment, the pharmacologically active agent according to general formula (I) is molecularly dispersed in a non-crystalline matrix.

In another preferred embodiment, the pharmacologically active agent according to general formula (I) is molecularly dispersed in a non-amorphous matrix. Preferably, the pharmacologically active agent according to general formula (I) is homogeneously distributed in the pharmaceutical dosage form according to the invention. The content of the pharmacologically active agent according to general formula (I) of two segments of the pharmaceutical dosage form having a volume of 1.0 mm ³ each, deviate from one another by preferably not more than ±10%, more preferably not more than more than ±7.5%, still more preferably not more than ±5.0%, most preferably not more than ±2.5%, and in particular not more than ±1.0%. When the pharmaceutical dosage form is encapsulated or film-coated, said two segments of the pharmaceutical dosage form having a volume of 1.0 mm ³ each are preferably segments of the core, i.e. do not contain any encapsulating medium or film coating, respectively.

Preferably, the pharmaceutical dosage form according to the invention is characterized by a comparatively homogeneous distribution of density. Preferably, the densities of two segments of the pharmaceutical dosage form having a volume of 1.0 mm ³ each, deviate from one another by not more than ±10%, more preferably not more than more than ±7.5%, still more preferably not more than ±5.0%, most preferably not more than ±2.5%, and in particular not more than ±1.0%. When the pharmaceutical dosage form is encapsulated, said two segments of the pharmaceutical dosage form having a volume of 1.0 mm ³ each are preferably segments of the core, i.e. do not contain any encapsulating medium or film coating.

In a preferred embodiment, the pharmaceutical dosage form further contains a surfactant.

For the purpose of the specification, the term "surfactant" refers to any compound that contains at least one hydrophobic group and at least one hydrophilic group. Preferably, the surfactant contains at least one terminal hydrophobic group (tail) and at least one terminal hydrophilic group (head).

The hydrophobic group is preferably selected from the group consisting of hydrocarbon, alkyl ether, fluorocarbon and siloxan groups.

In a preferred embodiment, the surfactant contains at least one aliphatic group comprising at least 3 carbon atoms, more preferably at least 4 carbon atoms, still more preferably at least 6 carbon atoms, yet more preferably 6 to 30 carbon atoms, and most preferably 8 to 24 carbon atoms. The aliphatic group may be a saturated or unsaturated, branched or unbranched (linear), terminal or internal aliphatic group. Preferably, the surfactant contains at least one group derivable from a saturated or unsaturated fatty acid or from a saturated or unsaturated fatty alcohol, which group is preferably an ether, carboxylic acid ester or sulfuric acid ester group. Preferably, the saturated or unsaturated fatty acid or fatty alcohol contains at least 6 carbon atoms, yet more preferably 6 to 30 carbon atoms, and most preferably 8 to 24 carbon atoms.

In a preferred embodiment, the surfactant contains at least one group derivable from a saturated or unsaturated fatty acid, preferably C ₆ to C ₃₀ fatty acid, more preferably C ₈ to C ₂₄ fatty acid, and most preferably Ci ₂ to C ₂₂ fatty acid. Examples for suitable fatty acids are lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, 12-hydroxystearic acid, oleic acid and ricinoleic acid.

In another preferred embodiment, the surfactant contains at least one group derivable from a saturated or unsaturated fatty alcohol, preferably C ₆ to C ₃₀ fatty alcohol, more preferably C ₈ to C ₂₄ fatty alcohol, and most preferably C ₁₂ to C ₂₂ fatty alcohol. Examples for suitable fatty alcohols are cetyl alcohol, stearyl alcohol, 2-octyldodecane-1-ol and 2-hexyldecane-1-ol.

Preferably, the surfactant has a molecular weight of at most 20,000 g/mol, more preferably at most 15,000 g/mol, still more preferably at most 10,000 g/mol, yet more preferably at most 5,000 g/mol, even more preferably at most 4,000 g/mol, most preferably at most 3,000 g/mol, and in particular within the range of from 100 g/mol to 2,500 g/mol.

Preferably, the surfactant is contained in a matrix in which the pharmacologically active agent according to general formula (I) is dispersed, preferably molecularly.

In a preferred embodiment, the pharmacologically active agent according to general formula (I) and the surfactant are intimately homogeneously distributed in a matrix so that the matrix does not contain any segments where either the pharmacologically active agent according to general formula (I) is present in the absence of the surfactant or where the surfactant is present in the absence of the pharmacologically active agent according to general formula

(") ^■

In a preferred embodiment, the pharmaceutical dosage form contains a surfactant. In another preferred embodiment, the pharmaceutical dosage form contains a mixture of two or more surfactants. In a preferred embodiment, the surfactant acts as an O/W emulsifier. In another preferred embodiment, the surfactant acts as a W/O emulsifier.

Preferably, the pharmaceutical dosage form contains a surfactant having a hydrophilic- lipophilic balance (HLB) of at least 10 or at least 11. More preferably, the hydrophilic- lipophilic balance (HLB) is at least 12 or at least 13. Most preferably, the hydrophilic-lipophilic balance (HLB) ranges within 14 and 16.

In another preferred embodiment, the hydrophilic-lipophilic balance (HLB) of the surfactant is at least 27, more preferably at least 29, still more preferably at least 31 , yet more preferably at least 33, even more preferably at least 35, most preferably at least 37 and in particular at least 39. An especially preferred surfactant of this type is sodium lauryl sulfate having an HLB value of about 40.

In a preferred embodiment, the HLB value of the surfactant is within the range of 10±3.5, more preferably 10±3, still more preferably 10±2.5, yet more preferably 10±2, even more preferably 10±1.5, most preferably 10±1 , and in particular 10±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 12±3.5, more preferably 12±3, still more preferably 12±2.5, yet more preferably 12±2, even more preferably 12±1.5, most preferably 12±1 , and in particular 12±0.5. In still another preferred embodiment, the HLB value of the surfactant is within the range of 14±3.5, more preferably 14±3, still more preferably 14±2.5, yet more preferably 14±2, even more preferably 14±1.5, most preferably 14±1 , and in particular 14±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 15±3.5, more preferably 15±3, still more preferably 15±2.5, yet more preferably 15±2, even more preferably 15±1.5, most preferably 15±1 , and in particular 15±0.5. In yet another preferred embodiment, the HLB value of the surfactant is within the range of 16±3.5, more preferably 16±3, still more preferably 16±2.5, yet more preferably 16±2, even more preferably 16±1.5, most preferably 16±1 , and in particular 16±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 18±3.5, more preferably 18±3, still more preferably 18±2.5, yet more preferably 18±2, even more preferably 18±1.5, most preferably 18±1 , and in particular 18±0.5.

In another preferred embodiment, the HLB value of the surfactant is within the range of 30±3.5, more preferably 30±3, still more preferably 30±2.5, yet more preferably 30±2, even more preferably 30±1.5, most preferably 30±1 , and in particular 30±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 32±3.5, more preferably 32±3, still more preferably 32±2.5, yet more preferably 32±2, even more preferably 32±1.5, most preferably 32±1 , and in particular 32±0.5. In still another preferred embodiment, the HLB value of the surfactant is within the range of 34±3.5, more preferably 34±3, still more preferably 34±2.5, yet more preferably 34±2, even more preferably 34±1.5, most preferably 34±1 , and in particular 34±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 36±3.5, more preferably 36±3, still more preferably 36±2.5, yet more preferably 36±2, even more preferably 36±1.5, most preferably 36±1 , and in particular 36±0.5. In yet another preferred embodiment, the HLB value of the surfactant is within the range of 38±3.5, more preferably 38±3, still more preferably 38±2.5, yet more preferably 38±2, even more preferably 38±1.5, most preferably 38±1 , and in particular 38±0.5. In another preferred embodiment, the HLB value of the surfactant is within the range of 40±3.5, more preferably 40±3, still more preferably 40+2.5, yet more preferably 40±2, even more preferably 40±1.5, most preferably 40±1 , and in particular 40±0.5.

The surfactant can be ionic, amphoteric or non-ionic.

Suitable amphoteric surfactants include phospholipids, in particular lecithins such as soya bean lecithins.

In a preferred embodiment, the pharmaceutical dosage form contains an ionic surfactant, in particular an anionic surfactant.

Suitable anionic surfactants include but are not limited to sulfuric acid esters such as sodium lauryl sulfate (sodium dodecyl sulfate, e.g. Texapon ^® K12), sodium cetyl sulfate (e.g. Lanette E ^® ), sodium cetylstearyl sulfate, sodium stearyl sulfate, sodium dioctylsulfosuccinate (docusate sodium), di-[2-ethylhexyl]-succinate; and the corresponding potassium or calcium salts thereof.

Preferably, the anionic surfactant has the general formula (ll-a)

C _n H _2n+1 0-S0 ₃ - M ⁺ (ll-a), wherein n is an integer of from 8 to 30, preferably 10 to 24, more preferably 12 to 18; and is selected from Li ⁺ , Na ⁺ , K ⁺ , NH ₄ ⁺ 1/2 Mg ²⁺ and 1/2 Ca ²⁺ .

Further suitable anionic surfactants include salts of cholic acid including sodium glycocholate (e.g. Konakion ^® MM, Cernevit ^® ), sodium taurocholate and the corresponding potassium or ammonium salts. In another preferred embodiment, the pharmaceutical dosage form contains a non-ionic surfactant. Suitable non-ionic surfactants include but are not limited to

- fatty alcohols that may be linear or branched, such as cetylalcohol, stearylalcohol, cetylstearyl alcohol, 2-octyldodecane-1-ol and 2-hexyldecane-1-ol;

- sterols, such as cholesterole;

- partial fatty acid esters of sorbitan such as sorbitanmonolaurate, sorbitanmonopalmitate, sorbitanmonostearate, sorbitantristearate, sorbitanmonooleate, sorbitansesquioleate and sorbitantrioleate;

- partial fatty acid esters of polyoxyethylene sorbitan (polyoxyethylene-sorbitan-fatty acid esters), preferably a fatty acid monoester of polyoxyethylene sorbitan, a fatty acid diester of polyoxyethylene sorbitan, or a fatty acid triester of polyoxyethylene sorbitan; e.g. mono- and tri- lauryl, palmityl, stearyl and oleyl esters, such as the type known under the name "polysorbat" and commercially available under the trade name "Tween" including Tween ^® 20 [polyoxyethylene(20)sorbitan monolaurate], Tween ^® 21 [polyoxyethylene(4)sorbitan monolaurate], Tween ^® 40 [polyoxyethylene(20)sorbitan monopalmitate], Tween ^® 60 [polyoxyethylene(20)sorbitan monostearate], Tween ^® 65 [polyoxyethylene(20)sorbitan tristearate], Tween ^® 80 [polyoxyethylene(20)sorbitan monooleate], Tween 81 [polyoxyethylene(5)sorbitan monooleate], and Tween ^® 85 [polyoxyethylene(20)sorbitan trioleate]; preferably a fatty acid monoester of polyoxyethylenesorbitan according to general formula (ll-b)

Alkylene CH ₃

o

(ll-b) wherein (w+x+y+z) is within the range of from 15 to 100, preferably 16 to 80, more preferably 17 to 60, still more preferably 18 to 40 and most preferably 19 to 21 ;

and alkylene is an optionally unsaturated alkylene group comprising 6 to 30 carbon atoms, more preferably 8 to 24 carbon atoms and most preferably 10 to 16 carbon atoms; polyoxyethyleneglycerole fatty acid esters such as mixtures of mono-, di- and triesters of glycerol and di- and monoesters of macrogols having molecular weights within the range of from 200 to 4000 g/mol, e.g., macrogolglycerolcaprylocaprate, macrogolglycerollaurate, macrogolglycerolococoate, macrogolglycerollinoleate, macrogol-20-glycerolmonostearate, macrogol-6-glycerolcaprylocaprate, macrogolglycerololeate; macrogolglycerolstearate, macrogolglycerolhydroxystearate (e.g. Cremophor ^® RH 40), and macrogolglycerolrizinoleate (e.g. Cremophor ^® EL);

- polyoxyethylene fatty acid esters, the fatty acid preferably having from about 8 to about 18 carbon atoms, e.g. macrogololeate, macrogolstearate, macrogol-15-hydroxystearate, polyoxyethylene esters of 12-hydroxystearic acid, such as the type known and commercially available under the trade name "Solutol HS 15"; preferably according to general formula (ll-c)

CH ₃ CH ₂ -(OCH ₂ CH ₃ )n-0-CO-(CH ₂ )mCH ₃ (ll-c) wherein n is an integer of from 6 to 500, preferably 7 to 250, more preferably 8 to 100, still more preferably 9 to 75, yet more preferably 10 to 50, even more preferably 11 to 30, most preferably 12 to 25, and in particular 13 to 20; and

wherein m is an integer of from 6 to 28; more preferably 6 to 26, still more preferably 8 to 24, yet more preferably 10 to 22, even more preferably 12 to 20, most preferably 14 to 18 and in particular 16;

- polyoxyethylene fatty alcohol ethers, e.g. macrogolcetylstearylether, macrogollarylether, macrogololeylether, macrogolstearylether;

- polyoxypropylene-polyoxyethylene block copolymers (poloxamers);

- fatty acid esters of saccharose; e.g. saccharose distearate, saccharose dioleate, saccharose dipalmitate, saccharose monostearate, saccharose monooleate, saccharose monopalmitate, saccharose monomyristate and saccharose monolaurate;

- fatty acid esters of polyglycerol, e.g. polyglycerololeate;

- polyoxyethylene esters of alpha-tocopheryl succinate, e.g. D-alpha-tocopheryl-PEG-1000- succinate (TPGS);

- polyglycolyzed glycerides, such as the types known and commercially available under the trade names "Gelucire 44/14", "Gelucire 50/13 and "Labrasol";

- reaction products of a natural or hydrogenated castor oil and ethylene oxide such as the various liquid surfactants known and commercially available under the trade name "Cremophor"; and - partial fatty acid esters of multifunctional alcohols, such as glycerol fatty acid esters, e.g. mono- and tri-lauryl, palmityl, stearyl and oleyl esters, for example glycerol monostearate, glycerol monooleate, e.g. glyceryl monooleate 40, known and commercially available under the trade name "Peceol"; glycerole dibehenate, glycerole distearate, glycerole monolinoleate; ethyleneglycol monostearate, ethyleneglycol monopalmitostearate, pentaerythritol monostearate.

Especially preferred surfactants of this class that are contained in the pharmaceutical dosage form according to the invention are non-ionic surfactants having a hydrophilic-lipophilic balance (HLB) of at least 10, in particular non-ionic surfactants having an HLB value of at least 12, more in particular non-ionic surfactant's having an HLB value within 14 and 16. Examples for this type of surfactants are the above-listed surfactants "Tween ^® 80" and "Solutol ^® HS 15".

Solutol ^® HS-15 is a mixture of polyethyleneglycol 660 12-hydroxystearate and polyethylene glycol. It is a white paste at room temperature that becomes liquid at about 30°C and has an HLB of about 15.

Tween ^® 80 [polyoxyethylene(20)sorbitan monooleate] is liquid at room temperature, has a viscosity of 375-480 mPa s and has an HLB of about 15.

In a preferred embodiment, the content of the surfactant is at least 0.001 wt.-% or at least 0.005 wt.-%, more preferably at least 0.01 wt.-% or at least 0.05 wt.-%, still more preferably at least 0.1 wt.-%, at least 0.2 wt.-%, or at least 0.3 wt.-%, yet more preferably at least 0.4 wt.-%, at least 0.5 wt.-%, or at least 0.6 wt.-%, and in particular at least 0.7 wt.-%, at least 0.8 wt.-%, at least 0.9 wt.-%, or at least 1.0 wt.-%, based on the total weight of the pharmaceutical dosage form.

In another preferred embodiment, particularly when the pharmaceutical dosage form contains an encapsulated core, the content of the surfactant is at least 10 wt.-%, more preferably at least 15 wt.-%, still more preferably at least 20 wt.-%, yet more preferably at least 25 wt.-% and in particular at least 30 wt.-%, based on the total weight of the composition forming the core. In a preferred embodiment, the content of the surfactant ranges preferably from 0.1 wt.-% to 95 wt.-%, more preferably from 1 wt.-% to 95 wt.-%, still more preferably from 5 wt.-% to 90 wt.-%, yet more preferably from 10 wt.-% to 80 wt.-%, most preferably from 20 wt.-% to 70 wt.-%, and in particular from 30 wt.-% to 75 wt.-%, based on the total weight of the composition forming the core. In another preferred embodiment, particularly when the pharmaceutical dosage form is a tablet, the content of the surfactant ranges preferably from 0.001 wt.-% to 95 wt.-%, more preferably from 0.01 wt.-% to 50 wt.-%, still more preferably from 0.1 wt.-% to 20 wt.-%, yet more preferably from 0.15 wt.-% to 15 wt.-%, most preferably from 0.20 wt.-% to 10 wt.-%, and in particular from 0.25 wt.-% to 5 wt.-%, based on the total weight of the dosage form. In a preferred embodiment, the content of the surfactant is at most 25 wt.-%, more preferably at most 20 wt.-%, still more preferably at most 15 wt.-%, yet more preferably at most 10 wt.-% and in particular at most 5 wt.-%, based on the total weight of the pharmaceutical dosage form. In case that the dosage form is coated, the indication "wt.-%" preferably refers to the weight of the surfactant per total weight of the composition forming the core, i.e. the pharmaceutical dosage form without its coating.

In a preferred embodiment, the content of the surfactant is within the range of 1.00±0.70 wt.- %, more preferably 1.00±0.60 wt.-%, still more preferably 1.00±0.50 wt.-%, yet more preferably 1.00±0.40 wt.-%, even more preferably 1.00±0.30 wt.-%, most preferably 1.00±0.20 wt.-%, and in particular 1.00±0.10 wt.-%

Preferred embodiments A ¹ to A ²⁰ of the pharmaceutical dosage form according to the invention are summarized in the table here below: embodiment A2 A3 A« ingredient nature content nature content nature content nature content pharmacologically

active agent according Y ⁱ 0.04±0.035 Y ⁱ 0.04±0.025 _Y 2 0.04±0.02 Y3 0.04±0.01 to general formula (I)

surfactant Z ⁱ 2.75±2.50 Z2 1.00±0.50 Z3 1.00±0.20 Z« 1.00±0.10 embodiment As A6 A' A» ingredient nature content nature content nature content nature content pharmacologically

active agent according Y ¹ 0.32±0.30 Y ⁱ 0.32±0.25 Y ² 0.32±0.20 _Y 3 0.32±0.10 to general formula (I)

surfactant Z 2.75±2.50 Z2 1.00±0.50 Z3 1.00+0.20 Z* 1.00±0.10 embodiment Aio A" A" ingredient nature content nature content nature content nature content pharmacologically

active agent according Ψ 0.50±0.45 Y ⁱ 0.50±0.30 _Y 2 0.50±0.20 _Y 3 0.50±0.10 to general formula (I)

surfactant 2.75±2.50 Z2 1.00±0.50 Z3 1.00±0.20 Z< 1.00±0.10 embodiment _A 13 A1 A« A« ingredient nature content nature content nature content nature content pharmacologically

active agent according Y ¹ 0.60±0.55 0.60±0.40 Y2 0.60+0.20 _Y 3 0.60±0.10 to general formula (I)

surfactant Z ⁱ 2.75±2.50 Z2 1.00±0.50 Z 1.00±0.20 Z" 1.00±0.10 wherein

nature refers to the chemical nature of the ingredient;

content refers to the content of the ingredient in wt.-% based on the total weight of the dosage form;

Y ¹ means pharmacologically active agent according to general formula (I) or a physiologically acceptable salt thereof;

Y ² means pharmacologically active agent according to general formula (Γ) or a physiologically acceptable salt thereof;

Y ³ means (I r^ -e'-fluoro-N.N-dimethyl-^phenyl-^.Q'-dihydro-S'H-spirotcyclo hexane-l .l '- pyrano[3 ,4,b]indol]-4-amine, or (1 r,4r)-6'-fluoro-N-methyl-4-phenyl-4',9'-dihydro-3'H- spiro[cyclohexane-1 ,1 '-pyrano[3,4,b]indol]-4-amine, or a physiologically acceptable salt thereof;

Z ¹ means surfactant having a HLB value of at least 10;

Z ² means anionic surfactant having a HLB value of at least 30;

Z ³ means anionic surfactant selected from the group consisting of sodium lauryl sulfate (sodium dodecyl sulfate, e.g. Texapon ^® K12), sodium cetyl sulfate (e.g. Lanette E ^® ), sodium cetylstearyl sulfate, sodium stearyl sulfate, sodium dioctylsulfosuccinate (docusate sodium), di-[2-ethylhexyl]-succinate; and the corresponding potassium or calcium salts thereof;

Z ⁴ means sodium lauryl sulfate.

For example, according to the above table, embodiment A ⁹ relates to a pharmaceutical dosage according to the invention, which contains the pharmacologically active agent according to general formula (I) in an amount of 0.50±0.45 wt.-% and a surfactant having a HLB value of at least 10 in an amount of 2.75±2.50 wt.-%, based on the total weight of the dosage form.

In a particular preferred embodiment, the pharmaceutical dosage form contains a surfactant having a HLB value of at least 10 in an amount of at least 0.001 wt.-%, based on the total weight of the pharmaceutical dosage form; and/or the pharmaceutical dosage form is for oral administration; and/or the pharmaceutical dosage form contains 0.01 % to 95 % of the pharmacologically active agent (A); and/or - the pharmaceutical dosage form has a weight within the range of from 0.1 mg to 2,000 mg; and/or the pharmaceutical dosage form contains a polymer with a molecular weight within the range of from 1 ,000 g/mol to 15 million g/mol; and/or the pharmaceutical dosage form is a tablet; and/or the pharmaceutical dosage form is prepared by means of wet granulation or direct tabletting; and/or

- the pharmaceutical dosage form contains the pharmacologically active agent according to general formula (I) in a dose of from 10 pg to 50 pg or of from 300 pg to 500 pg; and/or

- the pharmaceutical dosage form provides immediate release of the pharmacologically active agent according to general formula (I) in vitro in accordance with Ph. Eur.; and/or

- tmax is within the range of from 0.5 to 16 h; and/or

- the ratio AUC _0-t / dose is within the range of from 0.5 to 16.5 h/m ³ ; and/or ratio C _max / dose is within the range of from 0.06 to 1.69 m ^"3 .

In a preferred embodiment, the pharmaceutical dosage form according to the invention is a tablet, chewable tablet, chewing gum, coated tablet or powder, optionally filled into a capsule, but particularly preferably a tablet.

In another preferred embodiment, the pharmaceutical dosage form according to the invention is present in multi-particulate form, preferably in form of a micro-tablet, micro-capsule, granulate, pellet or active-substance crystal, particularly preferably in form of a micro-tablet, granulate or pellet, optionally filled into a capsule or compressed to form a tablet.

In an especially preferred embodiment, the pharmaceutical dosage form according to the invention is a tablet, which preferably has a diameter of 6±3.0 mm, more preferably of 6±2.5 mm, even more preferably of 6±2.0 mm, still more preferably of 6±1.5 mm, most preferably of 6±1.0 mm, and in particular of 6±0.5 mm.

The pharmaceutical dosage form according to the invention may contain pharmaceutical excipients including conventional antiadherents, binders, disintegrants, fillers, diluents, glidants, lubricants and preservatives, known to a person skilled in the art. A suitable antiadherent that may be contained in the pharmaceutical dosage form is magnesium stearate. In a preferred embodiment, the content of the antiadherent is within the range of from 0.001 to 5.0 wt.-%.

In a preferred embodiment, the pharmaceutical dosage form according to the invention further contains a binder. Suitable binders include but are not limited to gelatin, cellulose, modified cellulose such as microcrystalline cellulose, methyl cellulose, polyvinyl pyrrolidone, starch, sucrose and polyethylene glycol; especially preferred are polyvinyl pyrrolidone and/or microcrystalline cellulose. In a preferred embodiment, the content of antiadherent is within the range of from 0.001 to 30 wt.-%, more preferably 0.1 to 25 wt.-%.

In a preferred embodiment, the pharmaceutical dosage form according to the invention further contains a filler and/or diluent, preferably selected from the group consisting of but are not limited to cellulose, calcium diphosphate, lactose, sucrose, glucose, mannitol, sorbitol, and calcium carbonate; especially preferred are micro-crystalline cellulose and lactose. In a preferred embodiment, the content of filler and/or diluent is within the range of from 0.001 to 90 wt.-%, more preferably 0.1 to 80 wt.-%, most preferably 10 to 75 wt.-%.

In a preferred embodiment, the pharmaceutical dosage form according to the invention further contains a lubricant such as magnesium stearate, stearic acid and stearin. In a preferred embodiment, the content of the lubricant is within the range of from 0.001 to 5.0 wt.-%.

In a preferred embodiment, the pharmaceutical dosage form according to the invention further contains a disintegrant such as cross-linked sodium carboxymethyl cellulose (croscarmellose sodium), cross-linked polyvinyl pyrrolidone and sodium starch glycolate. In a preferred embodiment, the content of the disintegrant is within the range of from 0.001 to 5.0 wt.-%.

The pharmaceutical dosage form may further contain at least one preservative. Suitable preservatives include but are not limited to antioxidants, such as vitamin A, vitamin E, vitamin C, retinyl palmitate and selenium; cysteine, methionine, citric acid, sodium citrate, methyl paraben and propyl paraben. In a preferred embodiment, the pharmaceutical dosage form further contains a coating, in particular a polymer-based coating, more in particular a polyvinyl alcohol-based coating such as the ones commercially available under the trade name "Opadry".

Preferably, the coating protects the pharmaceutical dosage form from moisture, but dissolves rapidly in gastric juice. More preferably, the coated dosage form has a disintegration time of less than 5 minutes in gastric juice, more preferably of at most 4.5 minutes, still more preferably at most 4 minutes, yet more preferably at most 3.5 minutes, even more preferably at most 3 minutes, most preferably at most 2.5 minutes and in particular at most 2 minutes.

For the manufacture of the pharmaceutical dosage forms according to the invention, the various solid auxiliary substances and the pharmacologically active agent according to general formula (I) are preferably homogenized, processed by means of wet, dry or fusion granulation to form granulates, and compressed to form tablets. Alternatively, they are manufactured by direct tabletting of the auxiliary substances and the pharmacologically active agent according to general formula (I).

In a preferred embodiment, the pharmaceutical dosage form is prepared by means of wet granulation from a granulating fluid containing the pharmacologically active agent according to general formula (I), in particular from an aqueous granulating fluid containing said pharmacologically active agent and the surfactant. Preferably, the resulting granulating fluid is then top-sprayed or bottom-sprayed onto a solid formulation containing at least one auxiliary substance to yield compressible granules, which may optionally be mixed with further auxiliary substances before being compressed to tablets.

A further aspect of the invention relates to the pharmaceutical dosage form according to the invention as described above for use in the treatment of pain.

A further aspect of the invention relates to a method of treating pain comprising the twice daily, once daily, or less frequently, preferably oral administration of the pharmaceutical dosage form according to the invention to a subject in need thereof.

Preferably, the pain is selected from acute, visceral, neuropathic or chronic pain.

EXAMPLES

Prophetic examples: Prophetic examples of pharmaceutical dosage forms according to the invention are provided in Table 1 below. Their compositions are intended to be exemplary and it should be understood that the ingredients, the amount thereof and the procedure to obtain the dosage form may be varied.

For example, the ingredients of the following examples may be split up into intragranular and extragranular ingredients as well as ingredients from which a granulating solution is formed in order to process dosage forms by fluid bed granulation according to inventive example 1 ; or they may be processed by an alternative process, such as dry granulation or direct compression.

Table 1

Ingredients [mg] PE-1 PE-2 PE-3 PE-4 PE-5 PE-6

Lactose Monohydrate 69.65 69.65 64.00 64.00 59.65 59.65

Avicel® (PH101 or PH 102) 20.00 20.00 25.00 25.00 30.00 30.00

Croscarmellose sodium 3.00 3.00 2.50 2.50 3.00 3.00

Compound (I'b) 0.60 0.60 0.30 0.30 0.60 0.60

Polyvinyl pyrrolidone 5.00 5.00 5.50 5.50 5.00 5.00

Sodium cetylstearyl sulfate 1.00 - 2.00 - 1.00 -

Sodium dioctylsulfosuccinate - 1.00 - 2.00 - 1.00

Magnesium stearate 0.75 0.75 0.70 0.70 0.75 0.75

Non-prophetic examples:

The following examples further illustrate the invention but are not to be construed as limiting its scope.

Example 1 :

Pharmaceutical dosage forms were manufactured by fluid bed granulation according to the following compositions:

Table 2

Ingredients content (dosage: 40 g) content (dosage: 600Mg) amount per tablet amount per wt.-% % (w/w)

[mg] tablet [mg]

Intragranular

Lactose onohydrate (200 ) 50.21 50.21 49.65 49.65

Lactose Monohydrate (100 M) 20.00 20.00 20.00 20.00

Avicel® PH101 10.00 10.00 10.00 10.00

Croscarmellose sodium 1.50 1.50 1.50 1.50

Granulating Solution

Compound (I'b) 0.04 0.04 0.6 0.6

Polyvinylpyrrolidone 5.00 5.00 5.00 5.00

Sodium Lauryl Sulphate 1.00 1.00 1.00 1.00

Purified water - -

Extragranular

Croscarmellose sodium 1.50 1.50 1.50 1.50

Avicel® PH102 10.00 10.00 10.00 10.00

Magnesium stearate 0.75 0.75 0.75 0.75

Avicel® PH101 and Avicel® PH102 are microcrystalline celluloses with different mean particle sizes (50 and 100 microns). Purified water was used as part of the granulating fluid, but was removed during the granulation process.

General procedure

For the fluid bed granulation process, all intragranular ingredients [lactose monohydrate (200 M and 100 M), Avicel® PH101 , croscarmellose sodium] were weighed out and screened through a 710 micron screen into a 5 L Pharmatech shell. The material was then blended for 10 minutes at 25 rpm using a Pharmatech blender. The granulating solution was prepared by dissolving sodium lauryl sulfate in 600 g of purified water. 400 g of the corresponding solution was then used for dissolving the pharmacologically active agent according to formula ( ) (1 ,1-(3-methylamino-3-phenylpentamethylene)-6-fluoro-1 ,3,4,9-tetrahydropyrano[3,4-b]indole (trans)) and the binder (polyvinylpyrrolidone) to form a drug suspension. The drug suspension was top sprayed over the intragranular material at a suitable rate using the Diosna minilab machine to yield compressible granules. The compressible granules were then added to the extragranular ingredients (croscarmellose sodium, Avicel® PH102, magnesium stearate) and mixed. Compression into tablets was then performed on a single punch Manesty F3 compression machine using a 6.00 mm NCCP tooling. The tablets were coated by means of the polyvinyl alcohol-based coating system OPADRY® AMB.

For dosage 50 pg, the determined content of the decomposition product 6'-fluoro-4-phenyl- 4 ^, ,9'-dihydro-3 ^, H-spiro[cyclohex-3-ene-1 ,1'-pyrano[3,4-b]indole] after storage at 25°C and 60% rh as well as after storage at 40°C and 75% RH was < 0.1 % after 6 months.

EXAMPLE 2:

Clinical studies were conducted to determine the analgesic efficacy and tolerability of single doses of the compound according to formula (I'b) (200 pg, 400 pg and 600 pg, based on the content of the free base; hemicitrate oral solution of compound (I'b) in Macrogol 400) compared to that of morphine (60 mg, controlled-released form) and placebo in patients with acute post-operative pain following orthopedic surgery (bunionectomy).

For this purpose, 258 patients of either sex were included in a randomized, placebo- controlled, double-blind clinical trial in parallel groups. Treatment groups were well-balanced with respect to demographics and baseline characteristics with a slight imbalance in baseline pain and ethnicity.

After surgery, all patients were initially treated with local post-operative anesthesia via a popliteal block. Due to different kinetics of the compound according to formula (I'b) and morphine, the patients were then treated with either one of the two drugs or with placebo at slightly different times:

One hour before the popliteal block was stopped, patients were randomized and part of them were dosed with a single dose of the compound according to formula (I'b) (200 pg, 400 pg or 600 pg) or placebo, while the others received morphine or placebo 2 hours after the popliteal block had been stopped.

The primary efficacy assessment endpoint was the absolute pain intensity over a 24 hour period. Pain intensity was measured using an 11-point numerical rating scale (NRS). At each time point, patients were instructed to evaluate their current pain intensity relative to an 1 1 - point numerical rating scale. A score of zero represented no pain and a score of 10 represented worst possible pain. Missing scheduled pain assessments for the patients were imputed with the last observation carried forward (LOCF). The resulting averaged NRS values over the 24 hour period are depicted in Figure 1.

Sum of pain intensity differences over different time periods were analyzed using an analysis of covariance (ANCOVA) model with factors for treatment and site and baseline pain intensity score (using the pain intensity NPRS score). Only subjects with non-missing baseline pain intensity were included. A summary of the analysis for the 2 to 10 hour period is presented in Table 3. The resulting p-values are summarized in Table 4.

Table 3 n LS mean SE LS mean Aplacebo SE P-value placebo 45 49.13 2.85

compound (I'D) 200 pg 52 46.05 2.78 -3.08 3.49 0.3776

compound (I'D) 400 pg 47 35.28 2.81 -13.85 3.57 0.0001

compound (I'D) 600 pg 55 35.15 2.67 -13.98 3.45 < 0.0001 morphine, controlled-release 60 mg 49 42.01 2.83 -7.12 3.54 0.0454

LS mean: least squares means; SE: statistical error

Table 4 p-values 2-6 h 2-10 h 2-12 h 2-14 h 2-18 h 2-24 h

(sum of pain intensity differences)

compound (I'b) 200 pg 0.4514 0.3776 0.3387 0.3427 0.3205 0.2923 compound (I'b) 400 pg 0.0009 0.0001 < 0.0001 0.0001 0.0005 0.0008 compound (I'b) 600 pg 0.0009 < 0.0001 < 0.0001 < 0.0001 < 0.0001 0.0001 morphine, controlled-release 60 mg 0.4664 0.0454 0.0084 0.0036 0.0014 0.0005

Accordingly, on the primary parameter, a statistically significant difference was observed between groups that had received a 400 pg or 600 pg dose of compound (I'b) and placebo groups, whereas no statistically significant difference was observed for groups that had received a 200 pg dose of compound (I'b).

Tables 5 and 6 summarize the treatment emergent adverse events (TEAE(s)) experienced by the five treatment groups.

Table 5 related (n (%)) 17 (36.2) 24 (43.6) 32 (65.3) 43 (75.4) 42 (84.0) serious (n (%)) 1 (2.1) 0 0 0 0 total number of TEAE's (n) 74 75 125 198 144 related (n (%)) 32 (43.2) 37 (49.3) 74 (59.2) 146 (73.7) 99 (68.8) subjects with SAE's 1 (2.1) 0 0 0 0 deaths 0 0 0 0 0

TEAE: treatment emergent adverse event; SAE: serious adverse event

Table 6

100% = total number of subjects in corresponding treatment group;

ASAT: aspartate aminotransferase

It becomes evident from Tables 5 and 6 that all four active treatments were well tolerated under these circumstances and the adverse events that showed up most frequently are in line with what can be expected from μ-opioid receptor agonists. For the patient group that had been treated with compound (I'b), the incidence of adverse events increased with the dose, and at a dose of 600 pg the incidence of adverse events was comparable to that of the morphine patient group.

EXAMPLE 3:

Clinical studies were conducted to determine the bioavailability of a tablet formulation containing compound (I'b) in a dose strength of 400 pg compared to a hemicitrate oral solution of compound (I'b) (400 pg, 400 pg/mL oral solution) in a Macrogol 400 formulation after single oral administration. 24 healthy white male subjects were included in a randomized, open-label, 3-way crossover, single-center clinical trial. The main pharmacokinetic parameters were AUC _0- t, AUC _0- 72h and C _max .

The results are summarized in Tables 7 to 9.

Table 7 pharmacokinetic tmax [h] C _m ax [pg/mL] AUCo-72h [h pg/mL] AUCo-,[h pg/mL] parameter

400 g/mL 6.00 2861 ± 1251 4148 ± 2773

120 ± 45.9 (38.3%)

oral solution (2.08; 6.00) (43.7%) (66.8%) 400 g 6.00 3066 ± 1225 4501 ± 2658

135 ± 52.5 (38.8%)

tablet (3.50; 10.0) (40.0%) (59.1%)

N = 22; The table presents the arithmetic means +/- the standard deviation (coefficient of variation).

Table 8 comparison Cmax AUCo72h AUCo-t

tablets/oral solution

400 pg tablet / 108% 108% 110%

400 Mg/mL oral solution (101%-118%) (102%-115%) (103%-118%)

Table 9

n: number of subjects with at least one TEAE (treatment emergent adverse corresponding ratio of subjects experiencing TEAE(s); e: number of TEAE(s); *: 1-drop out due to unrelated adverse event

Accordingly, the relative bioavailability of the 400 pg tablet and 400 g/mL oral solution based on AUC _0-7 2h Was 108%, with 90%-CI within the 80% to 125% range used for assessing bioequivalence.

The relative bioavailability of the 400 g tablet and 400 Mg/mL oral solution based on C _max was also 108%, with 90%-CI within the 80% to 125% range used for assessing bioequivalence.

Single oral dose administrations of 400 g of compound (I'b) were safe and well tolerated independent from the galenic formulation. No serious adverse events occured.