Abstract:
The present invention relates to pharmaceutical compositions and formulations for the oral administration of Irbesartan, one of its pharmaceutically acceptable salts or its polymorphs, optionally combined with a diuretic and to a process for the manufacture of said composition.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to European Patent Application No. EP07380332.2, filed Nov. 28, 2007 and entitled “Pharmaceutical Formulations Containing Irbesartan” in the name of Marino Gonzalez Perez et al., incorporated herein by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to new pharmaceutical compositions and formulations for the oral administration of Irbesartan, one of its pharmaceutically acceptable salts or its polymorphs, optionally combined with a diuretic and to a process for the manufacture of said composition. 
       BACKGROUND OF THE INVENTION 
       [0003]    Irbesartan is an oral selective Angiotensin II antagonist pharmaceutically active compound useful for the treatment of hypertension and heart failure. The chemical name of Irbesartan is 2-n-butyl-4-spirocyclopentane-1-[((2′-tetrazol-5-yl)biphenyl-4-yl)methyl]-2-imidazolin-5-one with CAS Registry number 138402-11-6 and structural formula I. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0004]    The synthesis of Irbesartan is disclosed in EP0454511B1, EP0708103B1 and EP1853591 among other patent and patent applications. 
         [0005]    Irbesartan is marketed as Aprovel® in 75, 150 and 300 mg alone and as Coaprovel® in combination with hydrochlorothiazide (HCTZ, with structural formula II) in 150/12.5 mg and 300/25 mg strengths: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0006]    In EP0708103 there are described two polymorphic forms of Irbesartan, the polymorphic Forms A and B. 
         [0007]    Different formulations of Irbesartan are disclosed in the art. 
         [0008]    EP0747050A describes pharmaceutical formulations containing 20-70% irbesartan and a poloxamer as a surfactant to enhance dissolution. Granules of Irbesartan, diluent, binder, disintegrant and surfactant where prepared via wet granulation process using water. 
         [0009]    EP1089994A describes pharmaceutical compositions containing Irbesartan in a specific crystalline habit prepared according to EP0747050. 
         [0010]    EP1750862A describes pharmaceutical compositions containing more than 70% Irbesartan and a surfactant. Irbesartan is granulated with a solution of the binder and further granulated with more binder and the surfactant. 
         [0011]    EP1806130A describes surfactant free Irbesartan HCl formulations containing a disintegrant and a sugar alcohol as a diluent, Irbesartan is granulated with many ingredients, including mannitol, using alcohol 96%. 
         [0012]    EP 1670461 describes Irbesartan formulations containing a poloxamer (surfactant). The Irbesartan is granulated with the surfactant using alcohol 96%. 
         [0013]    EP1275391 describes pharmaceutical compositions of Irbesartan and a diuretic. Irbesartan and the diuretic are granulated with part of the diluent, part of the disintegrant and the binder using a wet granulation process with water. 
         [0014]    WO2007099555 describes irbesartan formulations with lactose and free of surfactant. 
         [0015]    As stated in EP0747050B1, Irbesartan shows certain physical properties that challenge the preparation of a suitable formulation containing the required amount of drug (75-300 mg) in a small easily to swallow tablet. Irbesartan is a fluffy material with low density, and then is difficult to handle it to prepare reproducible tablets. To obtain a good bioavailability, it is desired to obtain irbesartan tablets with total disgregation in less than 30 min. 
         [0016]    For all these reasons, there is still a need in the art for developing pharmaceutical compositions with small size which incorporate Irbesartan and methods suitable for industrial scale for preparing said compositions with an improved physical stability which allows desirable disgregation time and bioavailability properties. Furthermore, these new formulations need to allow preparing these tablets easily at an industrial scale. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0017]    The authors of the present invention have surprisingly found that a composition comprising Irbesartan as active ingredient, and maltose as diluent, allows obtaining homogeneous oral pharmaceutical formulations, such as tablets, with also a good flowability. In particular, the best results are obtained when Irbesartan is firstly granulated with a binder and a disintegrant and then mixed with maltose and other excipients. The use of maltose improves the results when compared to those obtained with lactose as diluent, since formulations with lactose result in bad fluidity and non-homogeneous formulations and also they could not be tabletted. 
         [0018]    Therefore, in a first aspect the present invention relates to a pharmaceutical composition comprising Irbesartan characterized in that it includes maltose. 
         [0019]    In a second aspect, the present invention relates to an oral pharmaceutical formulation which comprises the pharmaceutical composition as defined above. 
         [0020]    In a particular embodiment, the oral pharmaceutical formulation comprises:
       a. granules comprising Irbesartan, a binder and a disintegrant; and   b. a mixture of maltose, a disintegrant, a glidant, a lubricant and, optionally, an additional diluent.       
 
         [0023]    In another particular embodiment, the pharmaceutical formulation further comprises a diuretic inside the granules and/or out the granules. 
         [0024]    A third aspect of the present invention is a process for preparing an oral pharmaceutical formulation as defined above, more preferably a tablet, which comprises mixing and granulating the Irbesartan, the disintegrant and, optionally, the binder with water or a water solution of the binder to obtain the granules. 
         [0025]    In a particular embodiment, this process further comprises: a) mixing the granules previously obtained with maltose, the glidant, the disintegrant and, optionally, the additional diluent and the diuretic; b) mixing the mixture obtained in step a) with the lubricant; c) compressing the resulting mixture obtained in step b) to prepare a tablet; and d) optionally, coating the tablet. 
         [0026]    In another particular embodiment, the process further comprises mixing and granulating with the diuretic. In this case, the process further comprises: a) mixing the granules previously obtained with maltose, the glidant, the disintegrant, and, optionally, the additional diluent; b) mixing the mixture obtained in step a) with the lubricant; c) compressing the resulting mixture obtained in step b) to prepare a tablet; and d) optionally, coating the tablet. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    In the present invention the maltose is considered as defined in the US National Formulary 25. 
         [0028]    The present invention relates to a pharmaceutical composition comprising Irbesartan as active ingredient and maltose as a diluent. This composition allows obtaining oral pharmaceutical compositions, preferably tablets. 
         [0029]    In a particular embodiment of the invention, the oral pharmaceutical formulation is characterized by comprising:
       a) granules comprising Irbesartan, a binder and a disintegrant;   b) a mixture of maltose, a disintegrant, a glidant, a lubricant and, optionally, an additional diluent.       
 
         [0032]    In a particular embodiment, the pharmaceutical formulation further comprises a diuretic into the granules and/or out of the granules. 
         [0033]    More preferably, the granules comprise 67 to 97.5% by weight of Irbesartan; 2 to 12% by weight of a binder; 0.5 to 6% by weight of a disintegrant; and 0 to 15% by weight of a diuretic, said percentages being with respect to the total weight of the granules. 
         [0034]    In another preferred embodiment, the oral pharmaceutical formulation is characterized by the following total quantitative composition:
       20-87% by weight of Irbesartan;   10-25% by weight of maltose;   1-10% by weight of a binder;   1-9% by weight of a disintegrant;   0-15% by weight of an additional diluent;   0.1-3% by weight of a glidant;   0.5-3% by weight of a lubricant;   0-15% by weight of a diuretic;
 
said percentages being with respect to the total weight of the formulation.
       
 
         [0043]    Optionally, the granules of the formulation may comprise part of the maltose or of the additional diluent. Preferably the granules are formulated without maltose or additional diluent. 
         [0044]    The additional diluent used in the formulation of the present invention is selected from one or more of the list consisting of microcrystalline cellulose, cellulose powder, calcium hydrogen phosphate dihydrate, starch, maltose and a functional equivalent, excluding lactose monohydrate and anhydrous lactose. Preferably, the diluent is microcrystalline cellulose. 
         [0045]    The binder used in the formulation of the present invention is selected from one or more of the list consisting of povidone, hydroxypropylmethyl cellulose, pregelatinized starch, hydroxypropyl cellulose LH-21, starch and a functional equivalent. 
         [0046]    The disintegrant used in the formulation of the present invention is selected from one or more of the list consisting of croscarmellose sodium, crospovidone, carboxymethyl cellulose sodium, carboxymethyl starch sodium and a functional equivalent. 
         [0047]    The glidant used in the formulation of the present invention is selected from one or more of the list consisting of silica colloidal anhydrous, magnesium trisilicate, talc and a functional equivalent. 
         [0048]    The lubricant used in the formulation of the present invention is selected from one or more of the list consisting of magnesium stearate, stearic acid, glycerol dibehenate, talc and a functional equivalent. 
         [0049]    The Irbesartan used in the oral pharmaceutical formulations of the present invention is, preferably, Irbesartan polymorphic Form A as described in EP0708103. 
         [0050]    In a particular embodiment of the invention, when a diuretic is incorporated in the pharmaceutical formulation, said diuretic can be inside and/or out of the Irbesartan granules. Preferably, said diuretic is hydrochlorothiazide (HCTZ). 
         [0051]    In a preferred embodiment, the oral formulation of the invention is in the form of a tablet. 
         [0052]    In another particular embodiment, the oral formulation of the invention is further coated. 
         [0053]    In another aspect, the present invention relates to a process for preparing an oral pharmaceutical formulation as defined above using a wet granulation process, which comprises mixing and granulating the Irbesartan, the disintegrant and, optionally, part of the binder with water or a water solution of the binder. 
         [0054]    Optionally the Irbesartan can be granulated with part of the maltose or of the additional diluent. 
         [0055]    In a particular embodiment, 0-10% by weight of the binder is mixed with the Irbesartan and 90-100% by weight of the binder is used in the binder water solution. 
         [0056]    More preferably, all the binder is present in the binder water solution. 
         [0057]    In another particular embodiment, the process for preparing the Irbesartan oral pharmaceutical formulations of the present invention further comprises:
       a) mixing the granules obtained by the process as defined above, with the maltose, the glidant, the disintegrant and, optionally, the additional diluent and the optional diuretic;   b) mixing the mixture obtained in step a) with the lubricant;   c) compressing the resulting mixture obtained in step b) to prepare a tablet; and   d) optionally, coating the tablet.       
 
         [0062]    Even in another particular embodiment, when a diuretic is incorporated into the granules of the pharmaceutical formulation, the process for the preparation of said formulation further comprises mixing and granulating with the diuretic. 
         [0063]    In this case, the process for preparing the Irbesartan and diuretic oral pharmaceutical formulations of the present invention further comprises:
       a) mixing the granules obtained by the process as defined above, with the maltose, the glidant, the disintegrant and, optionally, the additional diluent;   b) mixing the mixture obtained in step a) with the lubricant;   c) compressing the resulting mixture obtained in step b) to prepare a tablet; and   d) optionally, coating the tablet.       
 
         [0068]    In the following, the present invention is further illustrated by examples. They should in no case be interpreted as a limitation of the scope of the invention as defined in the claims. 
       EXAMPLES 
     Example 1  
       [0069]    Quantitative Composition: 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 (g) 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Irbesartan 
                 75.00 
                 72.82 
               
               
                   
                 Lactose monohydrate 
                 12.31 
                 11.96 
               
               
                   
                 Povidone 
                 5.20 
                 5.00 
               
               
                   
                 Croscarmellose sodium 
                 3.10 
                 3.01 
               
               
                   
                 Microcrystalline Cellulose 
                 6.10 
                 5.93 
               
               
                   
                 Anhydrous colloidal silica 
                 0.26 
                 0.25 
               
               
                   
                 Magnesium stearate 
                 1.03 
                 1.00 
               
               
                   
                 Purified water* 
                 q.s. 
               
               
                   
                 Total weight 
                 103 
               
               
                   
                   
               
               
                   
                 *solvent which disappears during the wet granulation process. 
               
             
          
         
       
     
         [0070]    The Irbesartan, the lactose, the povidone and the croscarmellose sodium were granulated with water. Next, the granules were dried and sieved. Said granules were mixed with the cellulose microcrystalline, anhydrous colloidal silica and the magnesium stearate. 
         [0071]    When trying to compress the mixture it resulted in low flowability and impossible to compress the mixture. 
       Example 2  
       [0072]    Using the same quantitative composition as in example 1, the Irbesartan, the lactose, the povidone and half of the croscarmellose sodium were sieved, mixed and granulated with water. Next, the granulate was dried and sieved. 
         [0073]    The remaining croscarmellose sodium, the microcrystalline cellulose and the anhydrous colloidal silica were sieved and mixed together and then were mixed with the previously prepared granules. Finally, the magnesium stearate was added and mixed. When trying to compress the mixture it resulted in low flowability and impossible to compress the mixture. 
       Example 3  
       [0074]    Using the same quantitative composition as in example 1, the Irbesartan, the lactose and half of the croscarmellose sodium were sieved, mixed and granulated with a water solution of povidone. Next, the granulate was dried and sieved. 
         [0075]    The remaining croscarmellose sodium, the microcrystalline cellulose and the anhydrous colloidal silica were sieved and mixed together and then were mixed with the previously formed granules. Finally, the magnesium stearate was added and mixed. When trying to compress the mixture it resulted in low flowability and impossible to compress the mixture. 
       Example 4  
       [0076]    Using the same quantitative composition as in example 1, granules of Irbesartan where prepared with the Irbesartan, half the lactose and half of the croscarmellose sodium were sieved, mixed and granulated with a water solution of povidone. Next, the granulate was dried and sieved. 
         [0077]    The remaining lactose and croscarmellose sodium, the microcrystalline cellulose and the anhydrous colloidal silica were sieved and mixed together and then were mixed with the previously formed granules. Finally, the magnesium stearate was added and mixed. When trying to compress the mixture it resulted in low flowability and impossible to obtain homogeneous tablets. 
       Example 5  
       [0078]    Quantitative Composition: 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 (mg) 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Granules 
                   
                   
               
               
                   
                 Irbesartan 
                 75.00 
                 60.05 
               
               
                   
                 Lactose 
                 25.36 
                 20.31 
               
               
                   
                 Povidone 
                 6.44 
                 5.16 
               
               
                   
                 Croscarmellose sodium 
                 3.86 
                 3.09 
               
               
                   
                 Microcrystalline Cellulose 
                 12.62 
                 10.10 
               
               
                   
                 Anhydrous colloidal silica 
                 0.32 
                 0.26 
               
               
                   
                 Magnesium stearate 
                 1.29 
                 1.03 
               
               
                   
                 Purified water* 
                 q.s. 
               
               
                   
                 Total weight 
                 125 
               
               
                   
                   
               
               
                   
                 *solvent which disappears during the wet granulation process. 
               
             
          
         
       
     
         [0079]    The Irbesartan and half of the croscarmellose sodium were sieved, mixed and granulated with a water solution of povidone. Next, the granules were dried and sieved. 
         [0080]    The remaining croscarmellose sodium, the lactose, the microcrystalline cellulose and the anhydrous colloidal silica were sieved and mixed together and then were mixed with the previously formed granules. Finally, the magnesium stearate was added and mixed. When trying to compress the mixture it resulted in low flowability and impossible to obtain homogeneous tablets. 
       Example 6  
       [0081]    Quantitative Composition: 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 (mg) 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Granules 
                   
                   
               
               
                   
                 Irbesartan 
                 75.00 
                 60.00 
               
               
                   
                 Maltose 
                 12.73 
                 10.18 
               
               
                   
                 Povidone 
                 6.44 
                 5.15 
               
               
                   
                 Croscarmellose sodium 
                 1.93 
                 1.54 
               
               
                   
                 Purified water* 
                 q.s. 
               
               
                   
                 Extragranular 
               
               
                   
                 Maltose 
                 12.73 
                 10.18 
               
               
                   
                 Croscarmellose sodium 
                 1.93 
                 1.54 
               
               
                   
                 Microcrystalline Cellulose 
                 12.62 
                 10.10 
               
               
                   
                 Anhydrous colloidal silica 
                 0.32 
                 0.26 
               
               
                   
                 Magnesium stearate 
                 1.30 
                 1.04 
               
               
                   
                 Total weight 
                 125 
               
               
                   
                   
               
               
                   
                 *solvent which disappears during the wet granulation process. 
               
             
          
         
       
     
         [0082]    Following the procedure in Example 4 homogeneous tablets were prepared. The mixture showed good flowability properties, and the tablets could be properly compressed. The resulting tablets were homogeneous. 
         [0083]    Open Dish studies were performed on the resulting tablets at 30 days, the tablets dissolved in less than 30 minutes, and maintained good crushing and friability properties. 
       Example 7  
       [0084]    Quantitative Composition: 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 (mg) 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Granules 
                   
                   
               
               
                   
                 Irbesartan 
                 75.00 
                 58.25 
               
               
                   
                 Povidone 
                 6.44 
                 5.00 
               
               
                   
                 Croscarmellose sodium 
                 1.93 
                 1.50 
               
               
                   
                 Purified water* 
                 q.s. 
               
               
                   
                 Extragranular 
               
               
                   
                 Maltose 
                 25.47 
                 19.78 
               
               
                   
                 Croscarmellose sodium 
                 1.93 
                 1.50 
               
               
                   
                 Microcrystalline Cellulose 
                 12.62 
                 9.80 
               
               
                   
                 Anhydrous colloidal silica 
                 0.32 
                 0.25 
               
               
                   
                 Magnesium stearate 
                 1.29 
                 1.00 
               
               
                   
                 Coating 
                 3.75 
                 2.91 
               
               
                   
                 Total weight 
                 128.75 
               
               
                   
                   
               
               
                   
                 *solvent which disappears during the wet granulation process. 
               
             
          
         
       
     
         [0085]    Following the procedure in Example 5 homogeneous tablets were prepared. The mixture showed good flowability properties, and the tablets could be properly compressed. The resulting tablets were homogeneous. 
         [0086]    Open Dish studies were performed on the resulting tablets at 30 days, the tablets dissolved in less than 30 minutes, and maintained good crushing and friability 
       Example 8  
       [0087]    Quantitative Composition: 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 (mg) 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Irbesartan 
                 75.00 
                 53.19 
               
               
                   
                 Maltose 
                 25.36 
                 17.99 
               
               
                   
                 Povidone 
                 6.45 
                 4.57 
               
               
                   
                 Croscarmellose sodium 
                 3.71 
                 2.63 
               
               
                   
                 Microcrystalline Cellulose 
                 12.62 
                 8.95 
               
               
                   
                 Anhydrous colloidal silica 
                 0.32 
                 0.23 
               
               
                   
                 Magnesium stearate 
                 1.29 
                 0.91 
               
               
                   
                 HCTZ 
                 12.50 
                 8.87 
               
               
                   
                 Coating 
                 3.75 
                 2.66 
               
               
                   
                 Purified water* 
                 q.s. 
               
               
                   
                 Total weight 
                 141 
               
               
                   
                   
               
               
                   
                 *solvent which disappears during the wet granulation process. 
               
             
          
         
       
     
         [0088]    Following the procedure in Example 5, including the hydrochlorothiazide (HCTZ) out of the granules, homogeneous tablets were prepared. The mixture showed good flowability properties, and the tablets could be properly compressed. The resulting tablets were homogeneous. 
         [0089]    Open Dish studies were performed on the resulting tablets at 30 days, the tablets dissolved in less than 30 minutes, and maintained good crushing and friability properties. 
         [0090]    The following variations were performed to examples 6, 7 and 8. 
         [0091]    Instead of microcrystalline cellulose other diluents were tested: cellulose powder, calcium hydrogen phosphate dihydrate, starch and maltose. Similar results were obtained. 
         [0092]    Instead of povidone other binders were tested: hydroxypropylmethyl cellulose, pregelatinized starch, hydroxypropyl cellulose LH-21 and starch. Similar results were obtained. 
         [0093]    Instead of croscarmellose sodium other disintegrants were tested: crospovidone, carboxymethyl cellulose sodium and carboxymethyl starch sodium. Similar results were obtained. 
         [0094]    Instead of silica colloidal anhydrous other glidants were tested: magnesium trisilicate and talc. Similar results were obtained. 
         [0095]    Instead of magnesium stearate other lubricants were tested: stearic acid, glyceryl behenate and talc. Similar results were obtained.