SUSTAINED RELEASE TABLETS AND METHOD FOR PREPARATION THEREOF

摘要

The invention relates to sustained-release pharmaceutical preparations comprising a drug-containing tablet and a coating surrounding the same, wherein the coating is insoluble in water and gastrointestinal fluids and consists essentially of a terpolymer of polyvinylchloride, polyvinylacetate, and polyvinylalcohol and a water-soluble pore-creating substance, the said pore-creating substance being randomly distributed in the terpolymer coating, the ratio of pore-creating substance to terpolymer being from 1:10 to 20:1 by weight and said pore-creating substance being essentially pharmacologically inactive in the amount used. The invention also includes a method for the manufacture of the preparation.