OXIMINO-PIPERIDINE,-PYRROLIDINE AND-AZEPINE DERIVATIVES, THEIR PREPARATION AND THEIR USE AS MUSCARINIC RECEPTOR (ANT-) AGONISTES Background of Invention: The present invention relates to new compound having muscarinic activity.. The compound are useful in treating glaucoma, myopia, various other medical conditions that directly or indirectly involve muscarinic receptors within the human body. The invention is also directe to the treatment of glaucoma by controlling the principal symptom of that disease, elevated intraocular pressure. More specifically, the invention relates to the use of particular muscarinic compound to control intraocular pressure ("IOP") and thereby prevent or at least forestall progressive field of vision loss and other manifestations of glaucoma.

Glaucoma is a progressive disease which leads to optic nerve damage (i. e., glaucomatous optic neuropathy), and ultimately, partial or total loss of vision. The loss of visual field is secondary to the degeneration of optic nerve fibers which comprise the optic nerve. The causes of this disease have been the subject of extensive studies for many years, but are still not fully understood. However, it is known that a major risk factor for glaucomatous optic neuropathy is abnormally high IOP.

The usual reason for elevated IOP is an impairment of the outflow of fluid (i. e., aqueous humor) from the eye. Although hypersecretion of aqueous humor is not considered to be a common factor for elevated IOP, the pressure may be reduced by inhibiting the production (i. e., inflow, secretion or formation) of aqueous humor by the ciliary processes of the eye. Beta adrenoceptor blockers and carbonic anhydrase inhibitors are examples of drug classes that lower intraocular pressure by inhibiting the inflow of aqueous humor. Other classes of drugs reduce IOP by increasing the outflow of aqueous humor from the eye. Examples of these drug classes include miotics, such as pilocarpine and carbachol, and adrenergics or sympathomimetics, such as epinephrine.

While the use of the drug classes stated above is common practice in the medical therapy of glaucoma, it is not without side effets. Each class suffers from causing a particular set of side effects, locally and/or systemically, that is related to the pharmacological actions of that class.

For example, beta blockers, by blocking beta adrenoceptors in the heart can cause bradycardia or slow heart rate, and by blocking beta adrenoceptors in the bronchi can cause bronchoconstriction.

Systemic carbonic anhydrase inhibitors can cause malaise, headache, and other subjective symptoms which discourage their use by the patient. Muscarinic agents, such as pilocarpine, may be used to reduce IOP by increasing the outflow of aqueous humor, but the use of these agents frequently produces side effects such as miosis, impaire accommodation and/or browache.

Miosis is caused by the contractile effect of the muscarinic agents on the iris sphincter.

Muscarinic agents also have a contractile effect on the ciliary muscle. This effect is believed to be responsible for impairment of accommodation, as well as the browache experienced by some patients.

Thus, the agents used in glaucoma therapy show multiple pharmacological effects, some beneficial and some not. Since glaucoma medication must be taken over the patient's lifetime, it is advantageous to minimize the above-discussed side effects, so as to promote patients' compliance with the prescribed drug therapy, while maintaining the beneficial effect on intraocular pressure.

It has been estimated that one of every four persons suffers from myopia. About half or more of these cases are the result of elongation of the eye along the visual axis. At birth, the human eye is two-thirds the adult size. Through-out life the eye grows under the control of a finely tuned regulatory process. Anormal regulation of this mechanism can result in a lengthening of the eye, which results in the plane of focus being in front of the retina. This growth process is believed to be regulated by neural out-put from the retina. Although atropine, a muscarinic antagonist, has been used to retard the development of myopia, it use causes profond dilation of the pupil and impairs the ability to focus. The compound of this invention have minimal effects on pupil dilation and therefore offer an avantage over atropine or other compound having muscarinic activity that have been suggested as therapeutics for myopia.

Studies of muscarinic receptors have shown that there are multiple subtypes of muscarinic receptors, and that these receptor subtypes may be localized in different tissues, or may otherwise mediate different pharmacological effets. While some non-selective muscarinic agents may interact with multiple receptors and cause multiple effects, other muscarinic agents may interact more selectively with one or a combination of muscarinic receptor subtypes such that the beneficial effects are increased while the detrimental side-effects are reduced. For example, PCT International Publication Number WO 97/16196 indicates that certain 1- [cycloalkylpiperidin-4-yl]-2H benzimidazolones are selective muscarinic agonists of the m2 subtype with low activity at the m3 subtype, and when utilized for glaucoma therapy have fewer side effects than pilocarpine therapy.

The present invention is based on the discovery of new muscarinic compound and the use of these compound to treat glaucoma, myopia and other medical conditions. The following publications may be referred to for further background information regarding medical uses of compound having at least some structural similarities to the compound of the present invention: (1) PCT International Publication Number WO 97/24324 discloses 1- (1,2- disubstituted piperidinyl)-4-substituted piperidine derivatives as tachykinin receptor antagonists for treating pain; (2) PCT International Publication Number WO 97/16440 discloses 1- (1,2- disubstituted piperidinyl)-4-substituted piperazine derivatives as tachykinin receptor antagonists for treating pain; (3) PCT International Publication Number WO 97/16187 discloses 1,3-dihydro- l-[l-(l-heteroarylpiperazin-4-yl) cyclohex4-yl]-2H-benzimidazol-ones[l-(l-heteroarylpiperazin- 4-yl) cyclohex4-yl]-2H-benzimidazol-ones as muscarinic antagonists for treating and/or preventing myopia;

(4) United States Patent No. 5,574,044 discloses 1, 3-dihydro-1-{1-[piperidin-4- yl] piperidin-4-yl}-2H-benzimidazol-2-ones and 1, 3-dihydro-1-{4-amino-1-cyclohexyl}-2H- benzimidazol-2-ones as muscarinic antagonists for treating and/or preventing myopia; (5) United States Patent No. 5,691,323 discloses 1, 3-dihydro-1-{1-[piperidin-4- yl] piperidin-4-yl}-2H-benzimidazol-2-ones and 1,3-dihydro-1- {4-amino-1-cyclohexyl}-2H- benzimidazol-2-ones as muscarinic antagonists for treating and/or preventing myopia; (6) United States Patent No. 5,718,912 discloses the use of 1- [cycloalkylpioeridin-4-yl]-2H benzimidazolones to treat glaucoma; (7) United States Patent No. 5,461,052 discloses the use of tricyclic compound to prevent myopia; (8) United States Patent No. 5,122,522 discloses the use of pirenzepine and other muscarinic antagonists in the treatment of myopia; and (9) United States Patent No. 5,637,604 discloses the use of muscarinic antagonists in the treatment and control of ocular development.

Summary of the Invention: The present invention is directe to a new group of compound and to the use of these compound to treat various conditions that directly or indirectly involve muscarinic receptors.

The compound may also be used to treat the symptoms of other types of conditions or injuries, based on the action of the compound on muscarinic receptors. Examples of conditions that may be treated with the compound of the present invention include glaucoma, myopia, dry eye and dry mouth (xerostoma). The compound may also be utilized to treat conditions of the central nervous system, such as psychosis and Alzheimer's disease. The compound have analgesic properties, and my therefore be used to treat various types of pain.

As indicated above, the compound of the present invention are particularly useful in the treatment of glaucoma, based on the ability of the compound to regulate intraocular pressure or "IOP". Like pilocarpine, the compound of the present invention are believed to control IOP via an action on muscarinic receptors. However, they are more potent than pilocarpine in lowering IOP, and, at a dose that causes an equal reduction in IOP, demonstrate a reduced level of miosis.

The production of miosis (i. e., pupil constriction) has been a very troublesome side effect of pilocarpine therapy. The compound of the present invention are also believed to be relatively free of the other major side effects associated with pilocarpine therapy, namely, impairment of accommodation and browache.

Detailed Description of the Invention: The compound of the present invention have the following formula: wherein: R is H, lower alkyl, alkoxyl, arylalkyl, alkynyl, alkenyl or cycloalkyl; R', R2 and R3 are independently H, lower alkyl, halogen, lower alkoxyl, OH, HOCH2, aryl, arylalkyl, SR or N (R) 2; m and n are independently 0 or 1; o and p are independently 1 or 2; and X is C (R) 2, O, S (O)q, NR, C (=O), CHOR, C=NOR, NC (=O) OR, NC (=O) N (R) 2, NC (=O) R, CHC (=O) OR, CHC (=O) N (R) 2, CHC (=O) R, NS (O) 2C (R) 3,

wherein: q is 0,1 or 2; D is CH or N; E is C=O, S (=O), S (=O) 2 C=S or C=NR; and J is O, CR, C (R) 2, NR or NRC (=O).

In the foregoing description of the compound of formula (I), terms utilized to describe certain substituents (e. g., "alkyl") have the following meaning: The term"alkyl"includes straight or branche chain aliphatic hydrocarbon groups that are saturated and have 1 to 15 carbon atoms (Cl to Cl5). The alkyl groups may be substituted with other groups, such as halogen, hydroxyl or alkoxyl. Preferred straight or branche alkyl groups include methyl, ethyl, propyl, isopropyl, butyl and t-butyl.

The term"cycloalkyl"includes straight or branche chain, saturated or unsaturated aliphatic hydrocarbon groups which connect to form one or more rings, which can be fused or isolated. The rings may be substituted with other groups, such as halogen, hydroxyl or lower alkyl. Preferred cycloalkyl groups include cyclopropyl, cyclobutyl, cylopentyl and cyclohexyl.

The term"alkenyl"includes straight or branche chain hydrocarbon groups having 1 to 15 carbon atoms (C, to C, 5) with at least one carbon-carbon double bond. The chain hydrogens may be substituted with other groups, such as halogen. Preferred straight or branche alkenyl groups inclue, allyl, l-butenyl, l-methyl-2-propenyl and 4-pentenyl.

The term"alkynyl"includes straight or branche chain hydrocarbon groups having 1 to 15 carbon atoms (Cl to Cul5) with at least one carbon-carbon triple bond. The chain hydrogens may be substituted with other groups, such as halogen. Preferred straight or branche alkynyl groups inclue, 2-propynyl, 2-butynyl, 3-butynyl, 1-methyl-2-propynyl and 2-pentynyl.

The term"alkoxyl"represents an alkyl group attache through an oxygen linkage.

The term"lower alkyl"represents alkyl groups containing 1 to 6 carbons (C, to C6).

The term"lower alkoxyl"represents alkoxyl groups containing 1 to 6 carbons (Cl to C6).

The term"halogen"represents fluoro, chloro, bromo, or iodo.

The term"aryl"refers to carbon-based rings which are aromatic. Aromatic rings have alternating double and single bonds between an even number of atoms forcing a system which is said to'resonate'. The rings may be isolated, such as phenyl, or fused, such as naphthyl.

The ring hydrogens may be substituted with other groups, such as lower alkyl, or halogen.

The preferred compound of formula (I) are those wherein: R is lower alkyl, alkynyl or alkenyl; R', R2 and R3 are H or lower alkyl; m and p are 1; and X is CHOR, C=NOR, NC (=O) OR, NC (=O) N (R) 2, NC (=O) R, CHC (=O) OR, CHC (=O) N (R) 2 or CHC (=O) R.

Among these preferred compound, the most preferred are those wherein m, n, o and p are 1 and X is CHOR, C=NOR, NC (=O) OR, NC (=O) R, CHC (=O) OR or CHC (=O) N (R) 2.

Pharmaceutically acceptable salts of the compound of formula (I) may also be utilized in the present invention. Examples of such salts include inorganic and organic acid addition salts such as hydrochloride, hydrobromide, sulphate, phosphate, acetate, fumarate, maleate, citrate, lactate, tartrate, oxalate, or similar pharmaceutically acceptable inorganic or organic acid addition salts.

The compound of the present invention may be prepared by the method illustrated below:

Compound () is prepared by combining compound (1), (2) and a reducing agent such as sodium cyanoborohydride or sodium triacetoxyborohydride at a temperature of 20° C to 40° C and a pH in the range of 2-7. The ketal protecting group of compound () is removed by warming the compound in an acidic (hydrochloric acid, sulfuric acid, or trifluoroacetic acid) aqueous solution at a temperature ranging from 20° C to 100° C for 1 tol2 hours ("h"). An organic co-solvent such as methanol or tetrahydrofuran may be added to aid in the solubilization of the rection components. The resultant ketone (4) is converted in to. the oxime by adding the appropriately substituted hydroxylamine to the ketone (4) in a solvent such as methanol, ethanol or tetrahydrofuran and allowing the mixture to stir at a temperature between 0° C and 70° C for 2 to 24 h.

The starting materials L) and (2) are either commercially available or can be obtained by conventional procedures. The use of certain protecting groups and deprotecting steps may

be necessary, as will be appreciated by those skilled in the art. Compound of formula (3) may exist as mixtures of stereoisomers. The preparation of individual stereoisomers may be effected by the chromatographic separation of the stereoisomers or by the selective control of the rection conditions.

The compound of formula (I) are utilized to treat glaucoma, myopia and dry eye by topically applying a solution or other suitable ophthalmic composition containing the compound to the eye. The establishment of a specific dosage regimen for each individual patient is left to the discretion of clinicians. The amount of the compound applied to the eye with each dose may vary, depending on the severity of the condition being treated, the drug release characteristics of the compositions in which the compound is contained, and various other factors familiar to those skilled in the art. The amount of compound administered topically to the eye will generally be in the range of from about 0.3 to about 300 micrograms per dose, preferably from about 1 to about 100 micrograms per dose.

The compound may be administered by topically applying one to two drops of a solution or comparable amount of a microemulsion, suspension, solid, or semi-solid dosage form to the affecte eye (s) one to four times per day. The concentration of the compound of formula (I) in such compositions will vary, depending on the type of composition utilized. For example, it may be possible to use a relatively lower concentration of the compound when compositions which provide for sustained release of the compound or compositions which include a penetration enhancer are utilized. The concentrations generally will be in the range of from about 0.001 to about 1 percent by weight, based on the total weight of the composition ("wt. %"), preferably from about 0.01 to about 0.3 wt. %.

The compound of formula (I) may be included in various types of ophthalmic compositions. Since the compound are relatively stable and soluble in water, the compositions will generally be aqueous in nature. Aqueous solutions are generally preferred, based on ease of formulation, as well as patients'ability to easily administer such compositions by means of instilling one to two drops of the solutions in the affecte eyes. However, the compound may also be readily incorporated into other types of aqueous compositions, such as viscous or semi- viscous gels or other types of solid or semi-solid compositions.

In addition to the compound of formula (I) and the aqueous vehicles described above, the compositions of the present invention may also include one or more ancillary ingredients, such as preservatives, co-solvents and viscosity building agents.

Ophthalmic products are typically packaged in multidose form. Preservatives are thus required to prevent microbial contamination during use. Suitable preservatives include: benzalkonium chloride, thimerosal, chlorobutanol, methyl paraben, propyl paraben, phenylethyl alcool, edetate disodium, sorbic acid, polyquaternium l, or other agents known to those skilled in the art. Such preservatives are typically employed at a level of from 0.001% to 1.0% by weight.

In order to enhance the aqueous solubility of the compound of formula (I), a surfactant or other appropriate co-solvent may be included in the compositions. Such co-solvents include: polyethoxylated castor oils, such as those manufactured by BASF under the Cremophor brand; Polysorbate 20,60 and 80; nonionic surfactants, such as the following PluronicÆ brand surfactants of BASF: Pluronict F-68, F-84 and P-103; cyclodextrin; or other agents known to those skilled in the art. Such co-solvents are typically employed at a level of from 0.01% to 2% by weight.

Viscosity greater than that of simple aqueous solutions may be desirable to increase ocular absorption of the compound, to decrease variability in dispensing the formulations, to decrease physical separation of components of a suspension or mulsion of formulation and/or otherwise to improve the ophthalmic formulation. Such viscosity building agents inclue, for example, polyvinyl alcool, polyvinyl pyrrolidone, methyl cellulose, hydroxy propyl methylcellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxy propyl cellulose or other agents known to those skilled in the art. Such agents are typically employed at a level of from 0.01% to 2% by weight.

An appropriate buffer system (e. g., sodium phosphate or sodium acetate or sodium borate) may be added to prevent pH drift under storage conditions.

The compound of formula (I) may also be utilized to treat psychosis, Alzheimer's disease, dry mouth, pain and various other conditions. The compound may be administered by any convenient method, for example, by oral, parenteral, buccal, rectal or transdermal administration. The compound may be administered via conventional pharmaceutical compositions adapted for such administration. The compositions are generally provided in unit dose form (e. g., tables), comprising 0.5-100 mg of one or more compound of formula (I) in a pharmaceutically acceptable carrier, per each unit dose. The dosage of the compound is 1-300 mg/day, preferably 10-100 mg/day, when administered to patients, e. g. humans, as a drug. The compound may be administered one to four times a day.

The methods for synthesizing the compound of formula (I) and preparing the ophthalmic compositions of the present invention are further illustrated by the following examples. The term "Compound"in Examples 4 and 5 is intended to represent a compound of formula (I) or a pharmaceutically acceptable salt thereof.

Example 1 Preparation of 1- [1- (ethoxycarbonyl) piperidin-4-yl)-4- (O-allyloximino) piperidine hydro- chloride: Step 1 Preparation of I- [I- (ethoxycarbonyl) piperidin-4-yl] piperidine-4-oxo ethylene glycol ketal.

A solution of piperidin4-oxo ethylene glycol ketal (9.94 g, 69.4 mmol) and l-ethoxycarbonyl- 4-oxopiperidine (17.82 g, 104 mmol) and acetic acid (4.21 ml, 73.6 mmol) in dichloromethane (150) was stirred at room temperature for fifteen minutes. Then the solution was treated with sodium triacetoxy borohydride (23.53 g, 111 mmol) (the solution was weakly acidic, pH 5) with stirring at room temperature overnight. The mixture was evaporated and the resulting residue was dissolve in water (100 ml). The aqueous phase was washed with ether (50 ml X 6) and then the aqueous layer was basified with potassium carbonate (to pH10). The aqueous layer was extracted with dichloromethane (100 ml X 3). The combine organic layers were dried over magnesium sulfate and evaporated to a yellow oil, 19.25 g. This residue was

purifie by chromatography using silica gel and hexane/ethyl acetate (1: 1 -- > 4: 6--> 2: 8 -- > 0: 10) then eluted with methanol/dichloromethane (1: 9) to obtain 1- [I- (ethoxycarbonyl) piperidin-4-yl] piperidine-4-oxo ethylene glycol ketal as a colorless oil, 9.71 g (47%), MS (electrospray, M + H+ = 299 m/e).

Step 2 Preparation of 1- [l- (ethoxycarbonyl) piperidin-4-yl]-4-oxopiperidine.

1- [I- (ethoxycarbonyl) piperidin-4-yl] piperidine-4-oxo ethylene glycol ketal (7.59 g, 25.4 mmol) was dissolve in 2 N HUI (50 ml) and refluxed for five hours. The rection was quenched with potassium carbonate (to pH 10) and the mixture was extracted with dichloromethane (50 ml X 3). The organic layers were combine, dried over magnesium sulfate and evaporated to give 1- [I- (ethoxycarbonyl) piperidin-4-yl]-4-oxopiperidine as a colorless oil 3.43 g (53%), MS (electrospray, M + H+ = 255 m/e).

Step3 Preparation of 1-[1-(ethoxycarbonyl)piperidin-4-yl]-4-(O-allyloximino) piperidine hydro- chloride.

1-[1-(Ethoxycarbonyl)piperidin-4-yl]-4-oxopiperidine as (0.45 g, 1.75 mmol) was dissolve in methanol (10 ml) and treated with O-allyl hydroxylamine hydrochloride hydrate (o. 23 g, 2.1 mmol) and potassium carbonate (0.27 g, 1.9 mmol) with stirring at room temperature overnight. Saturated aqueous potassium carbonate (50 ml) was added and the mixture was extracted with dichloromethane (100 ml). The organic layer was washed with water (50 ml), dried with magnesium sulfate and evaporated to a colorless oil. The oil was treated with ethanolic hydrochloric acid and evaporated to give 1-[1-(ethoxycarbonyl)piperidin-4-yl]-4-(O- allyloximino) piperidine hydrochloride as a yellow solid, 0.42 g (70 %), mp 160-5 °C, MS (M + H+) = 310 m/e.

Example 2 Preparation of O-benzyl-1-[1-(ethoxycarbonyl) piperidin-4-yl] piperidin-3-one oxime hydro- chloride.

Step 1 Preparation of 1-[1-(ethoxycarbonyl) piperidin-4-yl] piperidin-3-one.

To a solution of oxalyl chloride (2.17 g, 17.1 mmol) in methylene chloride (20 mL) at-70°C under nitrogen was added DMSO (2.43 mL, 2.67g, 34.2 mmol) dropwise over 10 min. The mixture was stirred another 10 min before a solution of 1- [I- (ethoxycarbonyl) piperidin-4- yl] piperidin-3-ol (1.46 g, 5.70 mmol) in methylene chloride (2 mL) was added slowly over 5 min. After stirring for 30 min, TEA (5.76 g, 57 mmol) was added via syringe and the suspension was warmed to-20°C over about 20 min. Methanol (12 mL) was added and the rection was stirred for lh, evaporated to dryness, mixed with a saturated aqueous solution of sodium bicarbonate (30 mL) and extracted with EtOAc (100 mol). The combine extracts were dried over magnesium sulfate, filtered and evaporated to give an oil. Chromatography on silica (gradient, 50% to 100% EtOAc/Hex) gave 1.02 g of the title compound as an oil (70%): <BR> <BR> <BR> MS (EI) 255 (M+H);'H-NMR (CDC13) 8 244. (bs, 2H), 4.14 (q, J = 6.0 Hz, 2H), 3.12 (s, 2H), 2.75 (ion, 3H), 2.6-2.3 (ion, 3H), 2.0-1.7 (m, 5H), 1.49 (ion, 2 H), 1.26 (t, J = 6.0 Hz, 3H).

Step 2: Preparation of O-benzyl-1-[1-(ethoxycarbonyl) piperidin-4-yl] piperidin-3-one oxime hydro- chloride.

To a mixture of 1-[1-(ethoxycarbonyl) piperidin-4-yl] piperidin-3-one (0.33 g, 1.30 mmol) in MeOH/H2O (10 mL/10 mL) was added O-benzylhydroxylamine (0.31 g, 1.95 mmol) and sodium carbonate (0.276 g, 2.60 mmol). The mixture was heated at about 60°C for 2 h, and then stirred at ambient temperature overnight. Methanol was evaporated and the aqueous was extracted with EtOAc (3 x 20 mL). The combine extracts were dried over magnesium sulfate, filtered and evaporated to give a liquid. Chromatography on silica (gradient, 30% to 50% EtOAc/Hex) gave a liquid which was converted to HCI salt to provide the title

compound. MS (EI) 360 (M+H);'H-NMR (CDC13, free base, two conformers) 8 317. (ion, Ph, 5H), 5.05 (s, CH2Ph, 2H), 4.21 (bs, 2H), 4.11 (q, J = 7.0 Hz, 2H), 3.46,3.11 (s, 2H), 2.80- 2.20 (ion, 6 H), 1.73 (ion, 4 H), 1.46 (ion, 2 H), 1.25 (t, J = 7.0 Hz, 3 H).

Example 3 Preparation of O-Methyl-1-[1-(ethoxycarbonyl)piperidin-4-yl] piperidin-3-one oxime hydrochloride.

To a mixture of 1-[1-(ethoxycarbonyl) piperidin-4-yl] piperidin-3-one (0.33 g, 1.30 mmol) in MeOH/H2O (10 mL/10 mL) was added O-methylhydroxylamine HCl (0.163 g, 1.95 mmol) and sodium carbonate (0.276 g, 2.60 mmol). The mixture was heated at about 45°C for 3 h.

Methanol was evaporated and the residue was mixed with a saturated aqueous solution of sodium bicarbonate (10 mL) and extracted with methylene chloride (3 x 20 mL). The combine extracts were dried over magnesium sulfate, filtered and evaporated to give a liquid.

Chromatography on silica (gradient, 5% to 10% MeOH/CH2CI2) gave a liquid which was converted to HUI salt to provide the title compound. MS (EI) 284 (M+H) ;'H-NMR (CDC13, <BR> <BR> <BR> <BR> <BR> free base, two conformers) 8 224. (bs, 2H), 4.12 (q, J = 8.0 Hz, 2H), 3.40,3.10 (s, 2H), 2.80- 2.20 (m, 7 H), 1.73 (m, 4H), 1.46 (m, 2H), 1.25 (t, J = 8. 0 Hz, 3 H).

Example 4 The following formulation fou-ter illustrates the topical ophthalmic pharmaceutical compositions of the present invention.

Ingredient Amount (wt. %) Compound 0.1 Benzalkonium chloride 0.01 Edetate sodium 0.05 Sodium chloride q. s. to render isosmotic Hydrochloric acid q. s. to adjust pH and/or Sodium Hydroxide Purifie water q. s. to 100% of volume

Example 5 The following formulation fou-ter illustrates the systemic pharmaceutical compositions of the present invention, particularly oral tablet compositions.

Ingredient Amount Compound 5.0 mg Lactose 67.5 mg AvicelTM 31.5 mg mgAmberliteTM1.0 Magnesium Stearate 0.25 g