SUBSTAINED 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 pore-creating substance being present in amount of one part to 20 parts for each one to ten parts of terpolymer and being essentially pharmacologically inactive in the amount used. The invention also includes a method for the manufacture of the preparation.