SUSTAINED RELEASE MEDICINAL COMPOSITION FOR ORAL ADMINISTRATION CONTAINING NIFEDIPINE AS ACTIVE SUBSTANCE

摘要

PROBLEM TO BE SOLVED: To obtain the subject composition effective for treatment of essential hypertension and angina pectoris. SOLUTION: This composition is obtained by preparing 2.5-20wt.% nifedipine and polyvinylpyrrolidone in an amount of 1-5 pts.wt. based on 1 pt.wt. nifedipine in an organic solvent (methylene chloride), treating the resultant solution at 90 deg.C by a spraying and drying machine, introducing the resultant amorphous co-precipitate (having <100μm particle size), a hydrophilic cellulose derivative (e.g. hydrxypropyl methyl cellulose) in an amount of 0.1-6 pts.wt. and carboxypolymethylene in an amount of 0.1-5 pts.wt. based on 1 pt.wt. nifedipine and lactose by a fluidized bed method to prepare granules and applying a protective film or delayed surface agent film (e.g. acrylic acid polymer) to the granules. The composition can release nifedipine for 8-24hr. The nifedipine content in dosage unit is in the range of 0.1-400mg.