Cimetidine-containing solid pharmaceutical composition

PURPOSE: To obtain a long-acting pharmaceutical composition of an oral dosage form composed of cimetidine or its acid adduct coated with a release-retarding substance and optionally further a buffering agent stimulating the solubility of cimetidine in the intestine and exhibiting a specific dissolving behavior. CONSTITUTION: This composition is composed of cimetidine (its acid adduct) coated with a release-retarding substance such as polymethacrylic acid, an acrylic acid ester copolymer or hydroxypropylmethylcellulose phthalate, releases cimetidine in not more than 10% after 2hr in a 0.1N hydrochloric acid and exhibits releasing behavior shown in the table by the test using an European pharmacopoeia apparatus, in which a paddle is rotated at a speed of 100rpm, in 800ml of a buffer aqueous dissolving solvent containing 0.04mol of sodium hydroxide and monopotassium phosphate at 37°C. Alternatively, the composition is obtained by further adding a buffering agent having activity to make pH into a range of 3.5-6 in a 1%-aqueous solution, and the obtained composition release 50% or more of the cimetidine after 2hr at pH6.0 and 85% or more after 1hr at pH6.8 in the above-test. COPYRIGHT: (C)1992,JPO