Abstract:
The instant invention relates to pharmaceutical compositions containing c-Met kinase inhibitors. Also disclosed are processes for making said pharmaceutical compositions.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to formulations of c-Met kinase inhibitors. 
     A variety of c-Met kinase inhibitors have been disclosed for the treatment of various disorders related to c-Met kinase functioning, including the treatment of cellular proliferative disorders. Such disorders include, but are not limited to, cancer, hyperplasias, restenosis, cardiac hypertrophy immune disorders and inflammation. Representative examples of c-Met kinase inhibitors include those disclosed International Publication WO2008/008310, which published on Jan. 17, 2008, to Merck &amp; Co., Inc., which is hereby incorporated by reference in its entirety. 
     C-Met kinase inhibitors can be formulated for oral dosing as tablets, by using a direct compression, wet granulation, hot melt extrusion, spray drying and/or roller compaction method. Similarly, c-Met kinase inhibitors can be formulated for oral dosing as gelatin capsules, being a liquid in a soft capsule, or dry powder or semi-solid in a hard capsule. In addition, c-Met kinase inhibitors can be formulated for intravenous dosing. 
     The formulations of the instant invention have advantages over other formulations of c-Met kinase inhibitors. Many c-Met kinase inhibitors exhibit pH-dependent solubility through the pH range 1-7, having higher solubility in acidic pH. Based upon the sharp dependence of solubility on pH, it can be postulated that the performance of these formulations can vary based on variability in gastric pH. For example, recent data from clinical studies with Compound A indicated high variability in Compound A exposure among patients, with lower exposures in some patients who were concomitantly taking antacids (i.e. with high gastric pH). Exposure can vary due to many factors, including whether the inhibitor is taken with or without food. The formulations of the instant invention give in vivo exposures to the drug that are less sensitive to changes in gastric pH than other formulations. Hence while the formulations of the instant invention give a similarly high exposure to the drug at low gastric pH as other formulations, the formulations of the instant invention give a higher exposure to the drug at higher gastric pH than other formulations. 
     The use of acidulant as described in the instant invention is more efficacious than extemporaneous use of acidulant. For example, with the baseline of a simple formulation absent of acidulant, the improvement in drug solubilisation at high pH from the use of the instant invention is much greater than from coadministering an acidic beverage (e.g. cola). 
     SUMMARY OF THE INVENTION 
     The instant invention relates to pharmaceutical compositions containing c-Met kinase inhibitors. The pharmaceutical compositions of the instant invention give in vivo exposures to the drug that are less sensitive to changes in gastric pH than other formulations known in the art. Compared with other formulations known in the art, the formulations of the instant invention give a similarly high exposure to the drug at low gastric pH, but a higher exposure to the drug at higher gastric pH. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  describes the dissolution performance of the Compound A formulations described in Examples 1, 3, 4, 5, 6, 7 and a control formulation. 
         FIG. 2  describes the solubility measurements for Compound A HCl salt in 250 mL of SGF with various amounts of citric acid anhydrous pre-dissolved. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The instant invention relates to pharmaceutical compositions containing c-Met kinase inhibitors. The pharmaceutical compositions of the instant invention give in vivo exposures to the drug that are less sensitive to changes in gastric pH than other formulations known in the art. Compared with other formulations known in the art, the formulations of the instant invention give a similarly high exposure to the drug at low gastric pH, but a higher exposure to the drug at higher gastric pH. 
     A particularly effective c-Met kinase inhibitor is 1-[3-(1-Methyl-1H-pyrazol-4-yl)-5-oxo-5H-benzo[4,5]cyclohepta[1,2-b]pyridin-7-yl]-N-(pyridin-2-ylmethyl)methanesulfonamide, 
                                
which can be prepared by procedures described in: International Publication WO2008/008310, which published on Jan. 17, 2008, to Merck &amp; Co., Inc., which is hereby incorporated by reference in its entirety. This compound is also known as Compound A.
 
     The invention contemplates the use of any pharmaceutically acceptable fillers/compression aids, disintegrants, super-disintegrants, lubricants, binders, surfactants, film coatings, and solvents. Examples of these components are set forth below and are described in more detail in the Handbook of Pharmaceutical Excipients, Second Edition, Ed. A. Wade and P. J. Weller, 1994, The Pharmaceutical Press, London, England. 
     The instant invention comprises a pharmaceutical composition comprising from 5% to 80% by weight of a c-Met kinase inhibitor, 5% to 80% by weight of an acidulant, 0% to 90% by weight of a diluent, 0 to 15% by weight of a disintegrant and from 0 to 5.0% by weight of a lubricant. In a class of the instant invention, is a pharmaceutical composition comprising from 30% to 35% by weight of a c-Met kinase inhibitor, 40% to 45% by weight of an acidulant, 20% to 25% by weight of a diluent, 1.0% to 5.0% by weight of a disintegrant and from 0.5% to 2.0% by weight of a lubricant. 
     In an embodiment of the invention, the weight ratio of the c-Met kinase inhibitor to acidulant is selected from within a range of 0.3 to 5.0. 
     In an embodiment of the invention, the c-Met kinase inhibitor is 1-[3-(1-Methyl-1H-pyrazol-4-yl)-5-oxo-5H-benzo[4,5]cyclohepta[1,2-b]pyridin-7-yl]-N-(pyridin-2-ylmethyl)methanesulfonamide (Compound A) or a pharmaceutically acceptable salt thereof. 
     In an embodiment of the invention, the acidulent is selected from the group consisting of acetic, adipic, benzenesulphonic, benzoic, caprylic, cinnamic, citric, ethanedisulphonic, tartaric, ascorbic, maleic, glutamic, lactic, oxalic, L-Aspartic, 2-hydroxyethanesulfonic, pamoic, malonic, gentisic, salicylic, fumaric, glucoheptoic, gluconic, glucuronic, hippuric, lactobionic, laurylsulfuric, malic, malonic, mandelic, methanesulphonic, propionic, stearic, toluenesulphonic, undecylenic, camphorsulfonic and oleic acid. In a class of the invention, the acidulent is citric acid. 
     In an embodiment of the invention, the diluent is selected from the group consisting of microcrystalline cellulose, lactose, mannitol, calcium phosphate, calcium carbonate, magnesium carbonate, sucrose, glucose, sorbitol, calcium sulfate, powdered cellulose, silicified microcrystalline cellulose, cellulose acetate, compressible sugar, dextrates, dextrin, dextrose, ethylcelluose, fructose, glyceryl palmitostearate, kaolin, lactitol, magnesium carbonate, magnesium oxide, maltodextrin, maltose, medium-chain triglycerides, polydextrose, polymethacrylates, simethicone, sodium alginate, sodium chloride, tragacanth, trehalose, xylitol and starch. In a class of the invention, the diluent is microcrystalline cellulose. 
     In an embodiment of the invention, the disintegrant is selected from the group consisting of croscarmellose sodium, starch, crospovidone, sodium starch glycolate, calcium carbonate, sodium carbonate, magnesium carbonate, alginic acid, tribasic calcium phosphate, calcium carboxymethylcellulose, sodium carboxymethylcellulose, powdered cellulose, chitosan, colloidal silicon dioxide, guar gum, hydroxypropyl cellulose, magnesium aluminium silicate, methylcellulose, povidone, and sodium alginate. In a class of the invention, the disintegrant is croscarmellose sodium. 
     In an embodiment of the invention, the lubricant is selected from the group consisting of magnesium stearate, stearic acid, sodium stearyl fumerate, talc, calcium stearate, glycerin monostearate, glyceryl behenate, glyceryl palmitostearate, magnesium lauyl sulfate, medium chain triglycerides, poloxamer, sodium benzoate, sodium chloride, sodium lauryl sulfate and zinc stearate. In a class of the invention, the lubricant is magnesium stearate. 
     The instant invention further comprises a method of improving the absorption of a c-Met kinase inhibitor by administering a pharmaceutical composition comprising from 5% to 80% by weight of a c-Met kinase inhibitor, 5% to 80% by weight of an acidulant, 0% to 90% by weight of a diluent, 0 to 15% by weight of a disintegrant and from 0 to 5.0% by weight of a lubricant. In a class of the invention, the C-met kinase inhibitor is Compound A. In another class of the invention the acidulant is citric acid, the diluent is microcrystalline cellulose, the disintegrant is croscarmellose sodium and the lubricant is magnesium stearate. 
     The instant invention further comprises a method of improving the absorption of a c-Met kinase inhibitor by administering a pharmaceutical composition wherein the weight ratio of c-Met kinase inhibitor to acidulant is selected from within a range of 0.3 to 5.0. In a class of the invention, the C-met kinase inhibitor is Compound A and the acidulant is citric acid. 
     The instant invention further comprises a method of improving the dissolution performance and in vivo exposure of a formulation containing a c-Met kinase inhibitor by incorporating an acidulent into the formulation. The incorporation of the acidulent into the composition results in a greater dissolution performance and in vivo exposure corresponding to high gastric pH compared to having the same quantity of acidulent pre-dissolved in vitro or in vivo. 
     The pharmaceutical compositions of the present invention, including tablets and capsules, may also contain one or more additional formulation ingredients that may be selected from a wide variety of excipients known in the pharmaceutical formulation art. According to the desired properties of the composition, any number of ingredients may be selected, alone or in combination, based upon their known uses in preparing pharmaceutical compositions. Such ingredients include, but are not limited to, diluents, binders, compression aids, disintegrants, lubricants, glidants, stabilizers (such as dessicating amorphous silica), flavors, flavor enhancers, sweeteners, preservatives, colorants and coatings. 
     The term “tablet” as used herein is intended to encompass compressed pharmaceutical dosage formulations of all shapes and sizes, whether uncoated or coated. Substances which may be used for coating include hydroxypropylmethylcellulose, hydroxypropylcellulose, titanium dioxide, talc, sweeteners and colorants. 
     The term “capsule” as used herein is intended to encompass compressed pharmaceutical dosage formulations of all shapes and sizes, whether uncoated or coated. Substances which may be used for coating include hydroxypropylmethylcellulose, hydroxypropylcellulose, titanium dioxide, talc, sweeteners and colorants. Substances which may be used for coating include hydroxypropylmethylcellulose, hydroxypropylcellulose, titanium dioxide, talc, sweeteners and colorants. 
     The pharmaceutical compositions of the present invention are useful in the therapeutic or prophylactic treatment of disorders associated with c-Met kinase functioning, including the treatment of cellular proliferative disorders. Such disorders include, but are not limited to, cancer, hyperplasias, restenosis, cardiac hypertrophy immune disorders and inflammation. 
     The formulations of the instant invention ensure that the biological benefits of the c-met kinase inhibitor are experienced across the widest number of patients, including those with higher-than-normal gastric pH (e.g. those patients on gastric-pH modifying drugs such as proton pump inhibitors). The formulations of the instant invention should provide benefits in the presence of proton pump inhibitors, including, but not limited to, omeprazole, raberprazole, esomeprazole, lansoprazole and patoprazole; H-2 blockers, including, but not limited to, cimetidine, famotidine, nizatidine and ranitidine; and antacids, including, but not limited to, carafate, sodium bicarbonate, calcium carbonate, magnesium hydroxide and aluminum hydroxide. Additionally, the formulations of the instant invention are expected to reduce the variability in exposure that arises from natural inter-subject variations in gastric pH (not arising from pH modifying drugs). 
     The following examples are given for the purpose of illustrating the present invention and shall not be construed as being limitations on the scope of the invention. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A HCl salt 
                 31.00 
                 465.0 
               
               
                 Citric acid, anhydrous, fine 
                 41.94 
                 629.1 
               
               
                 powder 
                   
                   
               
               
                 Microcrystalline cellulose, 
                 23.06 
                 345.9 
               
               
                 Compendial (Avicel PH101) 
                   
                   
               
               
                 Croscarmellose sodium 
                 3.000 
                 45.0 
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 7.500 
               
               
                 [Non-bovine] (Intragranular) 
                   
                   
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 7.500 
               
               
                 [Non-bovine] (Extragranular) 
                   
                   
               
               
                 % Total 
                 100.0 
                 1500.0 
               
               
                   
               
             
          
         
       
     
     The capsules (HPMC shells) were prepared by encapsulating granule produced as follows. The citric acid, Avicel PH101, croscarmellose sodium and Compound A are mixed together in a drum blender. The intra-granular portion of the magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a blender. The lubricated blend was dry granulated using a roller compactor with in-built mill and coarse screen(s). The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a fine screen) and mixing using a blender. 
     
       
         
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Composition of the final material: 
               
             
          
           
               
                 Compound A free base 
                 15 
                 0.825 
               
               
                 Citric acid, anhydrous, fine 
                 5 
                 0.275 
               
               
                 powder (intra-comelt) 
                   
                   
               
               
                 Citric acid, anhydrous, fine 
                 15 
                 0.825 
               
               
                 powder (extra-comelt) 
                   
                   
               
               
                 Copovidone (VA 64) 
                 30 
                 1.65 
               
               
                 Microcrystalline cellulose (Avicel 
                 35 
                 1.925 
               
               
                 PH102) 
                   
                   
               
               
                 % Total 
                 100.0 
                 5.5 
               
             
          
           
               
                 Composition of the comelt intermediate: 
               
             
          
           
               
                 Compound A free base 
                 30 
                 7.5 
               
               
                 Citric acid, anhydrous, fine 
                 10 
                 2.5 
               
               
                 powder (intra-comelt) 
                   
                   
               
               
                 Copovidone (VA 64) 
                 60 
                 15 
               
               
                 % Total 
                 100.0 
                 25 
               
               
                   
               
             
          
         
       
     
     Compound A, the intra-comelt portion of citric acid, and the Kollidon VA64 were blended together in a glass bottle using a Turbula blender. The blend was manually fed into a 16 mm ThermoElectron extruder at Zone 7. Zones 2-8 were continuously cooled, while zones 9 and 10 were heated to a set point of 200° C. and a screw speed of 200 RPM. Extrudate emerging from the 3 mm circular orifice die were collected, air cooled, and subsequently milled using a Fitzmill set up with 0030 screen at 6500 RPM. 
     A sample of the comelt intermediate was then blended with the microcrystalline cellulose and the extra-comelt portion of citric acid in a glass bottle using a turbula blender. The lubricated blend was dry granulated by passing slugs (i.e. loose compacts made on a tablet press) through a coarse screen. The granular material was then filled into capsules. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A free base 
                 25.0% 
                 6.15 
               
               
                 Microcrystalline cellulose (Avicel 
                 24.2% 
                 5.953 
               
               
                 PH101) 
                   
                   
               
               
                 Citric Acid, Anhydrous, intra- 
                 17.8% 
                 4.38 
               
               
                 granular 
                   
                   
               
               
                 PVP (K29/32) 
                  3.6% 
                 0.8856 
               
               
                 Croscarmellose Sodium, intra- 
                  0.4% 
                 0.0984 
               
               
                 granular 
                   
                   
               
               
                 Magnesium Stearate, intra- 
                  0.5% 
                 0.123 
               
               
                 granular 
                   
                   
               
               
                 Citric Acid, Anhydrous, extra- 
                 25.0% 
                 6.149 
               
               
                 granular 
                   
                   
               
               
                 Croscarmellose Sodium, extra- 
                  3.0% 
                 0.738 
               
               
                 granular 
                   
                   
               
               
                 Magnesium Stearate, extra- 
                  0.5% 
                 0.123 
               
               
                 granular 
                   
                   
               
               
                 Total: 
                  100% 
                 24.6 
               
               
                   
               
             
          
         
       
     
     The tablets were prepared with a suitable press by compressing granule, prepared as follows. The Compound A and PVP were mixed together in a blender together with the intra-granular portions of Avicel, citric acid and croscarmellose sodium. The intra-granular portion of magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a drum blender. The lubricated blend was dry granulated using a roller compactor with in-built mill and coarse screen(s). The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a fine screen) and mixing using a blender. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A HCl salt 
                 26.94 
                 0.269 
               
               
                 Glutamic acid, anhydrous 
                 50.9 
                 0.509 
               
               
                 Microcrystalline cellulose, 
                 8.88 
                 0.089 
               
               
                 Compendial (Avicel PH101) 
                   
                   
               
               
                 Lactose Monohydrate 
                 8.88 
                 0.089 
               
               
                 Croscarmellose sodium 
                 3.4 
                 0.034 
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.005 
               
               
                 [Non-bovine] (Intragranular) 
                   
                   
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.005 
               
               
                 [Non-bovine] (Extragranular) 
                   
                   
               
               
                 % Total 
                 100.0 
                 1.000 
               
               
                   
               
             
          
         
       
     
     The capsules (hard gelatin shells) were prepared by encapsulating granule produced as follows. The glutamic acid, Avicel PH101, lactose monohydrate, croscarmellose sodium and Compound A are mixed together in a drum blender. The intra-granular portion of the magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a blender. The lubricated blend was dry granulated by passing slugs (i.e. loose compacts made on a tablet press) through a coarse screen. The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a screen) and mixing using a blender. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A HCl salt 
                 25.0 
                 0.400 
               
               
                 Ascorbic acid 
                 15.0 
                 0.240 
               
               
                 PVP K29/32 
                 5.0 
                 0.080 
               
               
                 Microcrystalline cellulose, 
                 22.0 
                 0.352 
               
               
                 Compendial (Avicel PH101) 
                   
                   
               
               
                 Lactose Monohydrate 
                 15.0 
                 0.352 
               
               
                 Croscarmellose sodium 
                 10 
                 0.160 
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.008 
               
               
                 [Non-bovine] (Intragranular) 
                   
                   
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.008 
               
               
                 [Non-bovine] (Extragranular) 
                   
                   
               
               
                 % Total 
                 100.0 
                 1.600 
               
               
                   
               
             
          
         
       
     
     The tablets were prepared using a tablet press by compressing granule produced as follows. The ascorbic acid, PVP, Avicel PH101, lactose monohydrate, croscarmellose sodium and Compound A are mixed together in a drum blender. The intra-granular portion of the magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a blender. The lubricated blend was dry granulated by passing slugs (i.e. loose compacts made on a tablet press) through a coarse screen. The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a screen) and mixing using a blender. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A HCl salt 
                 27.93 
                 1.185 
               
               
                 Maleic acid 
                 31.89 
                 1.353 
               
               
                 Microcrystalline cellulose, 
                 17.8 
                 0.755 
               
               
                 Compendial (Avicel PH101) 
                   
                   
               
               
                 Lactose Monohydrate 
                 17.8 
                 0.755 
               
               
                 Croscarmellose sodium 
                 3.53 
                 0.150 
               
               
                 Magnesium stearate, Compendial 
                 0.52 
                 0.022 
               
               
                 [Non-bovine] (Intragranular) 
                   
                   
               
               
                 Magnesium stearate, Compendial 
                 0.52 
                 0.022 
               
               
                 [Non-bovine] (Extragranular) 
                   
                   
               
               
                 % Total 
                 100.0 
                 4.242 
               
               
                   
               
             
          
         
       
     
     The capsules (hard gelatin shells) were prepared by encapsulating granule produced as follows. The maleic acid, Avicel PH101, lactose monohydrate, croscarmellose sodium and Compound A are mixed together in a drum blender. The intra-granular portion of the magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a blender. The lubricated blend was dry granulated by passing slugs (i.e. loose compacts made on a tablet press) through a coarse screen. The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a screen) and mixing using a blender. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Ingredient 
                 Unit Formula % w/w 
                 Amount (g) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Compound A HCl salt 
                 78.0 
                 7.000 
               
               
                 Citric acid, anhydrous, fine 
                 16.0 
                 1.436 
               
               
                 powder 
                   
                   
               
               
                 Sodium Lauryl Sulphate 
                 5.0 
                 0.449 
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.045 
               
               
                 [Non-bovine] (Intragranular) 
                   
                   
               
               
                 Magnesium stearate, Compendial 
                 0.5000 
                 0.045 
               
               
                 [Non-bovine] (Extragranular) 
                   
                   
               
               
                 % Total 
                 100.0 
                 8.974 
               
               
                   
               
             
          
         
       
     
     The capsules (hard gelatin shells) were prepared by encapsulating granule produced as follows. The citric acid, sodium lauryl sulphate and Compound A are mixed together in a drum blender. The intra-granular portion of the magnesium stearate (deagglomerated using a fine screen) was added to the mixture, and the mixture was lubricated using a blender. The lubricated blend was dry granulated using a roller compactor with in-built mill and coarse screen(s). The resultant granule was lubricated by adding the extra-granular portion of the magnesium stearate (deagglomerated using a fine screen) and mixing using a blender. 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
               
               
                   
                 Dose 
                   
                 AUC 0-24hr   
                 C max   
                 T max   
               
               
                 Formulation 
                 (mg) 
                 Pretreatment 
                 (μM * hr) 
                 (μM) 
                 (hr) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Control 
                 10 
                 Famotidine 
                  2.0 (1.2) 
                 0.2 (0.1) 
                 4 
                 (0.5, 4) 
               
               
                 Formulation (no 
                   
                   
                   
                   
                   
                   
               
               
                 organic acid) 
                   
                   
                   
                   
                   
                   
               
               
                 Control 
                 10 
                 Pentagastrin 
                 30.2 (6.5) 
                 4.3 (0.5) 
                 1.5 
                 (1-4) 
               
               
                 Formulation (no 
                   
                   
                   
                   
                   
                   
               
               
                 organic acid) 
                   
                   
                   
                   
                   
                   
               
               
                 Example 1 
                 10 
                 Famotidine 
                 18.4 (4.2) 
                 3.1 (0.6) 
                 2 
                 (1-4) 
               
               
                 Example 1 
                 10 
                 Pentagastrin 
                 29.0 (3.8) 
                 5.8 (0.8) 
                 2 
                 (1-2) 
               
               
                 Example 2 
                 10 
                 Famotidine 
                 20.5 (4.2) 
                 3.2 (0.7) 
                 2 
                 (1-2) 
               
               
                 Example 3 
                 10 
                 Famotidine 
                  4.7 (1.5) 
                 0.6 (0.2) 
                 3 
                 (1-4) 
               
               
                   
               
             
          
         
       
     
     Animal studies in high gastric pH (famotidine pretreated) beagle dogs were conducted to evaluate the formulations. In general, the formulations containing the citric acid (Examples 1 to 3) provided ˜2-10 fold higher exposures compared to the formulation that does not contain citric acid. These data support the claim that the formulations containing citric acid gave a higher exposure to the drug under higher gastric pH conditions than other formulations known in the art. Animal studies in normal gastric pH (pentagastrin pretreated) beagle dogs show that the formulation with citric acid (Example 1) gave a similarly high exposure to the drug as compared to the control formulation with no citric acid. 
     Note that the Control Formulation referred to above comprised hard gelatin capsules filled with a simple blend of Compound A free base, lactose monohydrate and magnesium stearate (x, y and z mg/capsule respectively) 
     Example 9 
     In Vitro Dissolution of Compound A Formulations 
     In vitro Dissolution, using USP apparatus II. 
     Dissolution media: SGF pH3.0 to make 1 L dissolve 2 g of NaCl in 1 L of water and adjust the pH to 3.0 using concentrated Hydrochloric acid. 
     Dissolution vessel temperature: 37° C. 
     Paddle speed: 100 rpm 
     Sample timepoints: 5, 10, 20, 30 minutes with additional timepoints taken as needed. 
     Sampling volume: 1.5 mL 
     Filter: Gelman acrodisc 1 μm glass fibre 
     Diluent: 50/50 Acetonitrile/Water+0.02% TFA (mix 500 mL of Acetonitrile with 500 mL of water and add 200 μL of TFA) 
     Sample dilution: Take 250 μL of filtered sample and dilute with 250 μL of diluent. 
     HPLC Method for the Analysis of Dissolution Samples: 
     Column: Phenomenex Luna C18, 4.6 mm×50 mm, 3 μm 
     Mobile Phase A: Water+0.02% TFA 
     Mobile Phase B: Methanol 
     Elution mode: Isocratic (45% B) 
     Column temperature: 45° C. 
     Injection volume: 2 μL 
     Detector wavelength: 260 nm 
     Flow rate: 2 mL/min 
     Run time: 2 minutes 
     From  FIG. 1  it can be seen that the Examples 1 &amp; 3-7, which are described in the instant invention, all give a higher extent of dissolution under relevant timescales (10-30 minutes) than the control formulation. 
     Note that the Control Formulation referred to in  FIG. 1  comprises hard gelatin capsules filled with a simple blend of Compound A free base, lactose monohydrate and magnesium stearate (50, 91 and 1.42 mg/capsule respectively). 
     Example 10 
     Solubility Measurements of Compound A 
     The graph in  FIG. 2  shows that the maximum solubility achieved for Compound A when 300 mg of citric acid is fully dissolved in 250 mL of SGF pH 3.0 is approximately 15 mg. This would equate to a 14% dissolved for a 110 mg potency capsule. However in a Compound A HCl Salt 110 mg HPMC capsule containing 42% by weight citric acid anhydrous, a measured approximately 78% dissolved is achieved; hence the formulation is improving the dissolution performance. Within this formulation the amount of citric acid anhydrous available is 160.44 mg (Target fill weight for the capsule is 382.0 mg)