FOR ANESTHESIOLOGICAL APPLICATIONS

CROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S.

Provisional Application No. 62/182,130, filed June 19, 2015, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of pharmacology and more specifically to compositions having anesthetic properties that are useful in various kinds of surgery, e.g., ophthalmic surgery, and to methods of preparing and using such compositions.

BACKGROUND

[0003] The present disclosure relates to solid or liquid pharmaceutical formulations comprising combinations of active agents such as anesthetics, anti-emetics, blood pressure, anti-anxiety medications and/or analgesics, and methods for using the same for providing anesthesia by administering such compositions orally, e.g., sublingually or bucally. The formulations may also include slow release reversal agents that would counteract the initial anesthesia effect.

[0004] It is necessary in many cases to use local anesthesia, particularly via oral route in the course of various surgical procedures, e.g., ophthalmic surgeries or urological interventions. For instance, when local anesthesia is employed during or prior to intraocular operations, the occurrences of pain, anxiety, peri-operative stress, nausea, agitation, vomiting and the like are less frequent, which will typically have a very beneficial effect on the surgical experience and reducing the number of intraocular complications such as bleeding, secretions, cardiac and/or pulmonary complications, etc. The severity of those complications when they do occur will also be less pronounced when local anesthesia is used.

[0005] Traditionally intravenous route is used to administer medications. Alternatives to intravenous methods and therapies have been suggested and previously used for the treatment. In particular, oral administration of benzodiazepines, opioid analgesics, propofol, ketamine or etomidate utilizing the MAC procedure (monitored anesthesia care) has been suggested and tried, l but no more than minimal to moderate improvement has been achieved by such methods.

Therefore, there remains a need for better treatments of these disorders.

[0006] This patent specification discloses such pharmaceutical compositions suitable for anesthesiological applications that can achieve positive patient outcomes while free of drawbacks and deficiencies of existing methods and formulations. Methods of fabricating and administering the same are also discussed.

SUMMARY

[0007] According to one embodiment of the invention, there are provided pharmaceutical compositions. The compositions include a therapeutically effective quantity of at least one first pharmaceutically active compound comprising benzodiazepine moiety or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof, a therapeutically effective quantity of at least one second pharmaceutically active compound that is an NMDA antagonist or

pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof, and at least one pharmaceutically acceptable excipient or carrier therefor.

[0008] According to another embodiment of the invention, the pharmaceutical compositions described above may further include a therapeutically effective quantity of at least one third pharmaceutically active compound that is a β-blocker or an antiemetic medicament, or a combination thereof, or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof.

[0009] According to further embodiments of the invention, in the pharmaceutical compositions described above, the first pharmaceutically active compound may be any of midazolam, diazepam, lorazepam, fiunitrazepam, alprazolam, chlordiazepoxide, clonazepam or clorazepate, the second pharmaceutically active compound may be any of ketamine, dextrorphan, etomidate, methadone, memantine, amantadine or dextromethorphan and the third pharmaceutically active compound may be (if a β-blocker) any of metoprolol, propranolol, acebutolol, nadolol, atenolol, betaxolol, esmolol, bisoprolol fumarate, carvedilol, nebivolol, penbutolol, timolol, or sotalol or (if an antiemetic) ondansetron, dolasetron, granisetron, palonosetron, promethazine, imenhydrinate, or meclizine.

[0010] According to yet another embodiment of the invention, there are provided further pharmaceutical compositions such as any described above, wherein the compositions are formulated as a liquid or a solid item, e.g., a troche, a lozenge, a capsule, a pill, a cap and a bolus suitable for sublingual or oral administration. [0011] According to other embodiments, there are provided specific compounds for making the compositions described above, for example, midazolam, ketamine and metoprolol, as well as methods for using above-mention composition(s) for the purposes of local anesthesia in various applications, such as ophthalmic surgery.

DETAILED DESCRIPTION

A. Terms and Definitions

[0012] Unless specific definitions are provided, the nomenclatures utilized in connection with, and the laboratory procedures and techniques of analytical chemistry, synthetic organic and inorganic chemistry described herein, are those known in the art. Standard chemical symbols are used interchangeably with the full names represented by such symbols. Thus, for example, the terms "hydrogen" and Ή" are understood to have identical meaning. Standard techniques may be used for chemical syntheses, chemical analyses, formulating compositions and testing them. The foregoing techniques and procedures can be generally performed according to conventional methods well known in the art.

[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. As used herein, the use of the singular includes the plural unless specifically stated otherwise. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0014] As used herein, "or" means "and/or" unless stated otherwise. Furthermore, use of the term "including" as well as other forms, such as "includes," and "included," is not limiting.

[0015] "About" as used herein means that a number referred to as "about" comprises the recited number plus or minus 1-10% of that recited number. For example, "about" 100 degrees can mean 95-105 degrees or as few as 99-101 degrees depending on the context. Whenever it appears herein, a numerical range such as "1 to 20" refers to each integer in the given range; i.e., meaning only 1, only 2, only 3, etc., up to and including only 20.

[0016] The term "pharmaceutical composition" is defined as a chemical or biological compound or substance, or a mixture or combination of two or more such compounds or substances, intended for use in the medical diagnosis, cure, treatment, or prevention of disease or pathology. [0017] The terms "anesthetic," "anesthesia," "anesthesiology" and the like refer herein to substances, compounds, processes or procedures that induce insensitivity to pain such as a temporary loss of sensation.

[0018] The terms "solvate" and "hydrate" are used herein to indicate that a compound or substance is physically or chemically associated with a solvent for "solvates" such as water (for "hydrates").

[0019] The term "NMDA antagonist" is defined as a compound that inhibits ("antagonizes") the action of the N-methyl-D-aspartate receptors and is inclusive of both competitive and noncompetitive antagonists, glycine antagonists and uncompetitive channel blockers, as these terms are understood by those having ordinary skill in the art.

[0020] The term "antiemetic" is defined as a drug or medicament that treats, reduces, and/or prevents nausea and/or vomiting.

[0021] The term "polyglycol" is defined as a polymer or oligomer containing several ether- glycol linkages that yields one or more glycols when these linkages are cleaved, e.g., by hydrolysis.

[0022] The term "carrier" refers to a substance that serves as a vehicle for improving the efficiency of delivery and the effectiveness of a pharmaceutical composition.

[0023] The term "excipient" refers to a pharmacologically inactive substance that is formulated in combination with the pharmacologically active ingredient of pharmaceutical composition and is inclusive of bulking agents, fillers, diluents and products used for facilitating drug absorption or solubility or for other pharmacokinetic considerations.

[0024] The term "binder" refers to a substance or compound that promotes, provides or improves cohesion, i.e., a substance that causes the components of a mixture to cohere to form a solid item that possesses integrity.

[0025] The term "troche" refers to a small tablet or lozenge (i.e., a medicated candy intended to be dissolved in the mouth), typically in a form of a disk, a ball or rhombic in cross-section, comprising medication and processed into a paste and dried. [0026] The term "therapeutically effective amount" is defined as the amount of the compound or pharmaceutical composition that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, medical doctor or other clinician.

[0027] The term "pharmaceutically acceptable" is defined as a carrier, whether diluent or excipient, that is compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

[0028] The terms "administration of a composition" or "administering a composition" is defined to include an act of providing a compound of the invention or pharmaceutical composition to the subject in need of treatment.

[0029] The terms "oral administration" and "orally administering" are broadly defined as a route of administration where a medication is taken through the mouth including "sublingual administration" and "buccal administration" where the medication is placed under the tongue or between the gums and the cheek, respectively, to be absorbed by the body.

B. Embodiments of the Invention

[0030] According to embodiments of the present invention, there are provided pharmaceutical compositions for anesthetic purposes. The compositions comprise, consist of or consist essentially of, a combination of therapeutically effective quantities of at least one first pharmaceutically active compound and at least one second pharmaceutically active compound. In some further embodiments, the compositions optionally comprise, in addition to the above-mentioned first and second pharmaceutically active compounds, at least one third pharmaceutically active compound.

[0031] The first pharmaceutically active compound that is used in such composition comprises benzodiazepine moiety or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof. Those having ordinary skill in the art will know that benzodiazepine moiety is a structure where a benzene ring is condensed with diazepine ring, a seven-member heterocycle with two nitrogen atoms which for the purposes of this specification may be in any positions of the ring (e.g., 1,2-diazepine, 1,3-diazepine or 1,4-diazepine). An example of a compound having benzodiazepine moiety with 1,4-diazepine structure is shown below:

[0032] One particular first pharmaceutically active compound comprising benzodiazepine moiety that can be used in pharmaceutical compositions described and claimed herein is midazolam. Other specific, non-limiting examples of first pharmaceutically active compounds comprising benzodiazepine moiety that can be used include diazepam, lorazepam, flunitrazepam, alprazolam, chlordiazepoxide, clonazepam, clobazam, bromazepam, prazepam, oxazepam and clorazepate. Each of these is also known under one or several trade names as shown in Table 1, which also discloses chemical names of such compounds. Those having ordinary skill in the art can select alternative suitable benzodiazepine-based compound for using in the compositions, if so desired.

Tablel . Examples of Benzodiazepine-Based Compounds That Can Be Used in Compositions

7-chloro-3-hydroxy- 5-phenyl-2,3-dihydro- Alepam®, Serax® and many

Oxazepam 1H- 1 ,4-benzodiazepine-2-one others

7-chloro-l-methyl-5-phenyl-l ,5- Urbanol®, Frisium®, Onfi®

Clobazam benzodiazepine-2,4(3H)-dione

7-chloro-l-(cyclopropylmethyl)-5-phenyl- Lysanxia®, Centrax® and many

Prazepam l,3-dihydro-2H-l ,4-benzodiazepin-2-one others

[0033] The therapeutically effective quantity of the benzodiazepine-based compound(s) in the entire pharmaceutical composition can be between about 0.2 mass % and about 5.0 mass % of the composition. In some embodiments, the therapeutic effective amount of the benzodiazepine-based compound(s) can be between about 1.0 mass % and about 3.0 mass %, for example, about 2.5 mass % of the composition.

[0034] In some applications a patient may be extra sensitive to benzodiazepines (e.g., may become excessively drowsy). For such patients, there are provided additional embodiments in which benzodiazepine(s)-containing pharmaceutical compositions described above, would additionally include a quantity of a receptor antagonist to benzodiazepines. Such a receptor antagonist would begin counteracting the effect of benzodiazepine after the surgical procedure is complete, in essence providing a slow release feature. A non-limiting example of this antagonist is fiumazenil also known under trade names such as Anexate®, Romazicon® and others.

[0035] The second pharmaceutically active compound that is used in such composition is an NMDA antagonist, as this term is defined hereinabove, or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof. One particular second pharmaceutically active compound that can be used in pharmaceutical compositions described and claimed herein is ketamine. Other specific, non-limiting examples of NMDA antagonists that can be used include dextrorphan, etomidate, methadone, memantine, amantadine and dextromethorphan. Each of these is also known under one or several trade names as shown in Table 2, which also discloses chemical names of such compounds. Those having ordinary skill in the art can select alternative suitable NMDA antagonists for using in the compositions, if so desired.

Table 2. Examples of NMDA Antagonists That Can Be Used in Compositions

Etomidate Ethyl-3-[(lR)-l-phenylethyl]imidazole-5-carboxylate Amidate®, Hypnomidate®

Methadone 6-(dimethylamino)-4,4-diphenylheptan-3-one Dolophine®, Amidone® and others

Memantine 3,5-dimethyladamantan-l -amine Akatinol®, Namenda® and others

Amantadine Adamantan- 1 -amine Symmetrel®

Dextromethorphan (4bS,8aR,9S)-3-methoxy-l l-methyl-6,7,8,8a,9,10- Robitussin®, Delsym® and hexahydro-5H-9,4b-(epiminoethano)phenanthrene others

[0036] The therapeutically effective quantity of the NMDA antagonist(s) in the entire

pharmaceutical composition can be between about 1.0 mass % and about 10.0 mass % of the

composition. In some embodiments, the therapeutically effective amount of the NMDA

antagonist(s) can be between about 4.0 mass % and about 6.0 mass %, for example, about 5.0 mass % of the composition. Accordingly, the combined quantities of both the benzodiazepine-based compound(s) and the NMDA antagonist(s), taken together, in the entire pharmaceutical

composition can be between about 1.2 mass % and about 15.0 mass % of the composition, such as between about 3.0 mass % and about 12.0 mass %, for example, about 10.0 mass % of the

composition.

[0037] As mentioned above, the compositions may further optionally comprise at least one third pharmaceutically active compound. In such embodiments, the third pharmaceutically active

compound is a β-blocker, as this term is defined hereinabove, or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof. In addition to, or instead of, β-blockers, the third

pharmaceutically active compound may also comprise an antiemetic medicament, as this term is defined hereinabove, or pharmaceutically acceptable salts, hydrates, solvates or N-oxides thereof.

[0038] The therapeutically effective quantity of the third pharmaceutically active compound(s) in the entire pharmaceutical composition can be between about 0.1 mass % and about 5.0 mass % of the composition. In some embodiments, the therapeutic effective amount of the third

pharmaceutically active compound(s) can be between about 1.0 mass % and about 4.0 mass %, for example, about 2.5mass % of the composition.

[0039] One particular β-blocker that can be used as the third pharmaceutically active compound in pharmaceutical compositions described and claimed herein is metoprolol. Other specific, non- limiting examples of β-blockers that can be used include, propranolol, acebutolol, nadolol,

atenolol, betaxolol, esmolol, bisoprolol fumarate, carvedilol, nebivolol, penbutolol, timolol and sotalol. Each of these is also known under one or several trade names as shown in Table 3, which also discloses chemical names of such compounds. Those having ordinary skill in the art can select alternative suitable β-blockers for using in the compositions, if so desired.

Table 3. Examples of β-Blockers That Can Be Used in Compositions

[0040] One particular antiemetic that can be used as the third pharmaceutically active compound in pharmaceutical compositions described and claimed herein is ondansetron. Other specific, non- limiting examples of antiemetics that can be used include dolasetron, granisetron, palonosetron, promethazine, imenhydrinate, and meclizine. Each of these is also known under one or several trade names as shown in Table 4, which also discloses chemical names of such compounds. Those having ordinary skill in the art can select alternative suitable antiemetics for using in the compositions, if so desired. Table 4. Examples of Antiemetics That Can Be Used in Compositions

[0041] Therefore, the combined quantities of all the pharmaceutically active compounds (i.e., the benzodiazepine-based compound(s), the NMDA antagonist(s), the -blocker(s)), and/or the antiemetic(s) taken together, in the entire pharmaceutical composition can be between about 1.3 mass % and about 20.0 mass % of the composition, such as between about 3.0 mass % and about 12.0 mass %, for example, about 10.0 mass % of the composition. Those having ordinary skill in the art will determine the most appropriate quantities of each the pharmaceutically active compound that are within the above-mentioned ranges and that are most suitable for a particular patient. As a guideline only, the following mass ratios between the pharmaceutically active compounds may be used (Table 5) for compositions where the benzodiazepine-based compound is midazolam, the NMDA antagonist is ketamine hydrochloride and the β-blocker is propanolol hydrochloride:

Table 5. Exemplary Mass Ratios Between Midazolam, Ketamine Hydrochloride and Propanolol

Hydrochloride in the Compositions Such as between about 1 4 1 and about 1 6 1

For example 1 5 1

[0042] In one specific embodiment, which is exemplary and non-limiting, for the composition having midozalam as the first pharmaceutically active compound, ketamine as the second pharmaceutically active compound and ondansetron at the third pharmaceutically active compound, the mass midazolam:ketamine:odansentron ratio may be about 3 :25 :2.

[0043] The pharmaceutical compositions described herein may contain not only

pharmaceutically active components but also, in some embodiments, may further comprise one or several inactive, neutral compounds which can be pharmaceutically acceptable excipient(s) or carrier(s), including, but not limited to, binder(s), antioxidant(s), adjuvant(s), synergist(s) and/or preservative(s). The mass concentration of such inactive compounds can be between about 80 mass % and about 99 mass % of the entire pharmaceutical composition, such as between about 85 mass % and about 95 mass %, e.g., about 90 mass %.

[0044] Some embodiments of the invention are directed to pharmaceutical formulations that are formulated as solid articles suitable for sublingual or oral administration, such as troches, lozenges, capsules, pills, caps or boluses. These solid compositions typically comprise binder(s) and/or excipient(s). They can be prepared by first mixing the pharmaceutically active compounds described above with suitable binder(s) and/or excipient(s) followed by molding or compressing the blend. Both hard and chewable lozenges and troches are within the scope of the invention.

[0045] Typical binder(s) that can be used for fabricating solid articles mentioned above include, without limitation, poly glycols as defined above, such as, e.g., polyethylene glycols (PEGs), polyethylene oxides (POE), methoxypoly ethylene glycols, polypropylene glycols, polybutylene glycols or derivatives thereof having a molecular weight that is sufficient to provide the necessary hardness and time for dissolution of the troche; for example, the acceptable molecular weight can be within the range of between about 1 ,000 Daltons and about 8,000 Daltons. In some

embodiments PEG-1450 or PEG-400 can be used. Non-limiting examples of some specific poly glycol derivatives that can be used are:

(a) PEG-laureates and dilaureates (e.g., PEG-10-, PEG-12-, PEG-20-, PEG-32-laurates, PEG-20- and PEG-32-dilaurates, PEG-20-glyceryl-, PEG-30-glyceryl- and PEG-40-glyceryl- laurates, PEG-80-sorbitan laurate); (b) PEG-oleates, dioleates and trioleates (e.g., PEG-12-, PEG-15-, PEG-20-, PEG-32, PEG-200- and PEG-400-oleates, PEG-20- and PEG-32- dioleates, PEG-20-trioleate, PEG-25- glyceryl trioleate, PEG-20-glyceryl- and PEG-30-glyceryl-oleates, PEG-40-sorbitan oleate);

(c) PEG-stearates and distearates (e.g., PEG- 15-, PEG-40-, PEG-100-stearates, PEG- 32-distearate and PEG-20-glyceryl stearate)

(d) castor, palm kernel, corn and soya oil derivatives of PEG (e.g., PEG-35-, PEG-40- and PEG-60-castor oils, PEG-40-, PEG-50- and PEG-60-hydrogenated castor oils, PEG-40-palm kernel oil, PEG-60-corn oil, PEG-30-soya sterol);

(e) other PEG derivatives (e.g., PEG-24- and PEG-30-cholesterol, PEG-25-phytosterol, PEG-6- and PEG-8-caprate/caprylate glycerides, tocopheryl PEG-100 succinate, PEG-15-100 octylphenol products and PEG-10-100 nonylphenol products);

(f) other products such as polyglyceryl-10-laurate, POE-9- and POE-23-lauryl ethers, POE-10- and POE-20-oleyl ethers, POE-20-stearyl ether, polysorbates-20 and 80, poly glyceryl- 10- oleate, Tween 40, Tween 60, sucrose monostearate, monolaurate and monopalmitate and various products of Poloxamer series.

[0046] Typical excipient(s) that can be used for fabricating solid articles mentioned above include, without limitation, gelatin, sodium saccharin, stevioside, peppermint oil, cherry flavor, lemon oil and raspberry flavor.

[0047] As stated above, the compositions may optionally further comprise one or several antioxidant(s). If antioxidant(s) are used, non-limiting examples of those that can be used include a-tocopherol acetate, acetone sodium bisulfite, acetylcysteine, ascorbic acid, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxy toluene, cysteine, cysteine hydrochloride, tocopherol natural, tocopherol synthetic, dithiothreitol, monothioglycerol, nordihydroguaiaretic acid, propyl gallate, sodium bisulfite, sodium formaldehyde sulfoxylate, sodium metabisulfite, sodium sulfite, sodium thiosulfate, thiourea and tocopherols.

[0048] As stated above, the compositions may optionally further comprise one or several adjuvant(s) or synergists(s). If adjuvant(s) or synergists(s) are used, non-limiting examples of those that can be used include citric acid, EDTA (ethylenediaminetetraacetate) and salts, hydroxy quinoline sulfate, phosphoric acid and tartaric acid. [0049] As stated above, the compositions may optionally further comprise one or several preservative(s). If preservative(s) are used, non-limiting examples of those that can be used include benzalkonium chloride, benzethonium chloride, benzoic acid and salts, benzyl alcohol, boric acid and salts, cetylpyridinium chloride, cetyltrimethyl ammonium bromide, chlorobutanol, chlorocresol, chorhexidine gluconate or chlorhexidine acetate, cresol, ethanol, imidazolidinyl urea, metacresol, methylparaben, nitromersol, o-phenyl phenol, parabens, phenol, phenylmercuric acetate/nitrate, propylparaben, sodium benzoate, sorbic acids and salts, β-phenylethyl alcohol and thimerosal.

[0050] The pharmaceutical formulation can be administered to a subject in need thereof by various local administrations. For example, the formulation can be used prior to various outpatient surgeries and medical procedures, such as an ophthalmic surgery, pediatric outpatient surgical procedures or urological procedures. In one non-limiting embodiment, the local administration is by oral route, such as sublingually or bucally.

[0051] It will be understood by those having ordinary skill in the art that the specific dose level and frequency of dosage for any particular patient may be varied and will depend upon many factors including the activity of the specific compound employed, the metabolic stability and length of action of that compound, the age, body weight, general health, gender, diet and the severity of the particular condition being treated.

[0052] According to further embodiments, methods for fabricating the above-described pharmaceutical compositions are provided. A one-batch formulation method may be used, where the components of the pharmaceutical formulation can be combined in single container; the components may be added to the container simultaneously or consecutively. Alternatively, a two- or multiple-batch method(s) may be used if desired, where each component of the pharmaceutical formulation can be combined in separate container followed by combining the contents of each container.

[0053] In one exemplary, non-limiting procedure, pre-measured quantities of each ingredient in the form of dry powder can be mixed to form a dry blend followed by mixing it with a pre-molten troche base. The composition can then be molded to form a troche.

[0054] In additional embodiments, pharmaceutical kits are provided. The kit includes a sealed container approved for the storage of solid pharmaceutical compositions, the container containing one of the above-described pharmaceutical compositions an instruction for the use of the composition and the information about the composition are to be affixed to the container or otherwise enclosed with it.

[0055] The following examples are provided to further elucidate the advantages and features of the present invention, but are not intended to limit the scope of the invention. The examples are for the illustrative purposes only. USP pharmaceutical grade products were used in preparing the formulations described below.

Example 1. Preparing a Pharmaceutical Composition in the Form of a Troche

[0056] A pharmaceutical composition may be prepared as described below. The following products can be used in the amounts and concentrations specified:

(a) about 0.2 g of midazolam;

(b) about 2.0 g of ketamine hydrochloride;

(c) about 0.2 g of propanolol hydrochloride;

(d) about 1 mL of lemon oil flavoring; and

(e) about 15.5 g of standard troche base (comprising polyglycol 1450, polyglycol 400, gelatin, sodium saccharin and steviaside).

[0057] The troche base can be melted at low heat while being stirred; when completely molten, the heat can be turned off with continued stirring. All the dry ingredients, pre-weighed can be added into the molten base followed by adding the flavoring and well mixed together.

[0058] A half-moon shaped troche mold can be lightly sprayed with Pam (or a suitable oil/releasing agent) to cover the entire surface of the mold and the mixture prepared as explained above can then be poured into the mold and allowed to cool and harden at room temperature. A heat gun can then be used to smooth out the surface followed by another round of cooling at room temperature followed by removing the so prepared troche from the mold, placing it into a prescription vial and labeling the vial. The troche is now ready to be administered.

[0059] Although the invention has been described with reference to the above examples, it will be understood that modifications and variations are encompassed within the spirit and scope of the invention. Accordingly, the invention is limited only by the following claims.