Novel dosage forms of risedronate

Abstract

The present invention is directed to a novel enteric-coated oral dosage form of a risedronate active ingredient comprised of a safe and effective amount of a pharmaceutical compostion which is comprised of a risedronate active ingredient and pharmaceutically-acceptable excipients. Said dosage forms prohibit the exposure of the risedronate active ingredient to the epithelial and mucosal tissues of the buccal cavity, pharynx, esophagus, and stomach and thereby protects said tissues from erosion, ulceration or other like irritation. Accordingly, the said dosage forms effect the delivery to the lower intestinal tract of said human or other mammal of a safe and effective amount of the risedronate active ingredient, and substantially alleviate the esophagitis or esophageal irritation which sometimes accompanies the oral administration of risedronate active ingredients.

What is claimed is:  
     
         1 . A novel enteric-coated oral dosage form of a risedronate active ingredient comprised of a safe and effective amount of a pharmaceutical composition comprising a risedronate active ingredient and pharmaceutically-acceptable excipients.  
     
     
         2 . A dosage form according to  claim 1  wherein said pharmaceutical composition is comprised of from 0.25% to 40.00% of a risedronate active ingredient and from 60.00 to 99.75% of pharmaceutically-acceptable excipients.  
     
     
         3 . A dosage form according to  claim 2  wherein the enteric coating is a pH-dependent coating and said oral dosage form is a delayed-release pharmaceutical composition.  
     
     
         4 . A dosage form according to  claim 3  wherein said enteric coating is insoluble at pH below 5.5 but soluble at pH 5.5 or above.  
     
     
         5 . A dosage form according to  claim 3  wherein said enteric coating is insoluble in the gastrointestinal fluids of the buccal cavity, pharynx, esophagus, and stomach, but soluble in the gastrointestinal fluids of the small and large intestine.  
     
     
         6 . A dosage form according to  claim 3  wherein said coating is comprised of anionic carboxylic polymers.  
     
     
         7 . A dosage form according to  claim 6  wherein said anionic carboxylic polymer is a partly-methyl-esterified methacrylic acid polymer wherein the ratio of anionic free carboxyl groups to ester groups is about 1:1.  
     
     
         8 . A dosage form according to  claim 3  wherein said enteric coating is insoluble at a pH below 7.0 and soluble in pH 7.0 or above.  
     
     
         9 . A dosage form according to  claim 4  wherein said enteric coating is insoluble in the gastrointestinal fluids of the buccal cavity, pharynx, esophagus, stomach, and small intestine but soluble in the gastrointestinal fluids of the large intestine.  
     
     
         10 . A dosage form according to  claim 9  wherein said coating is comprised of anionic carboxylic polymers.  
     
     
         11 . A dosage form according to  claim 10  wherein said anionic carboxylic polymer is a partly-methyl-esterified methacrylic acid polymer wherein the ratio of anionic free carboxyl groups to ester groups is about 1:2.  
     
     
         12 . A dosage form according to  claim 2  wherein the enteric coating is a pH-independent coating and said oral dosage form is a sustained-release pharmaceutical composition.  
     
     
         13 . A dosage form according to  claim 12  wherein said enteric coating is a polymer selected from the group consisting of ethylcellulose, hydroxypropylmethylcellulose, and carboxymethylcellulose.  
     
     
         14 . A dosage form according to  claim 12  wherein said dosage form is a tablet characterized by a core comprising a risedronate active ingredient upon which core there is provided a first inner layer of a diffusion membrane composed of ethylcellulose, polyethyl acrylate, methyl methacrylate, trimethylammonium ethyl methacrylate chloride, or mixtures thereof, and on said inner layer there is provided an outer layer of excipient material having a pKa of 4.5 to 7.0.  
     
     
         15 . A novel oral dosage form according to  claim 1  wherein said dosage form is a compressed tablet comprising particles of the risedronate active ingredient and pharmaceutically-acceptable excipients.  
     
     
         16 . An oral dosage according to  claim 15  wherein said compressed tablet is enterically coated.  
     
     
         17 . An oral dosage according to  claim 15  wherein said compressed tablet is comprised of particles of risedronate active ingredient which have been enterically coated.  
     
     
         18 . An oral dosage form according to  claim 17  wherein said compressed tablet is enterically coated.  
     
     
         19 . A novel oral dosage form according to  claim 1  wherein said dosage form is a capsule containing beads of the risedronate active ingredient which are themselves enterically coated.  
     
     
         20 . A novel oral dosage form according to  claim 1  wherein said dosage form is a capsule containing granules of the risedronate active ingredient which are themselves enterically coated.  
     
     
         21 . A novel oral dosage form according to claims  19  and  20  wherein said capsule is itself enterically coated.  
     
     
         22 . A novel oral dosage form according to claims  16 ,  17 ,  18 ,  19 ,  20 , and  21  wherein the enteric coating is comprised of a pH-dependent coating material.  
     
     
         23 . An oral dosage form according to  claim 22  wherein said coating material is insoluble at a pH below 5.5 and soluble at a pH 5.5 or above.  
     
     
         24 . A method of treating diseases characterized by abnormal calcium and phosphate metabolism, comprising administering to a human or other mammal in need of such treatment a safe and effective amount of a risedronate active ingredient delivered to said human or other mammal the novel oral dosage form of  claim 1.