Zensei Pharmaceutical Industries Co., Ltd.

This paper compare the release and pharmacokinetic characters of nifedipine from polymer coated tablets with other market-available nifedipine tablets.It was found the coated tablets from Zensei Pharmaceutical Industries Co., Ltd. is comparable with others.

A new controlled drug release system with zero-order sustained release property was developed using a gel-forming matrix.We report here the release characteristics of the newly developed release system, its formulation and reproducibility.This tablet preparation was composed of a gel-forming matrix containing a drug substance as a core, which was then coated with a water-insoluble layer.With absorbing water into the gel matrix through the coated layer and swelling the matrix, the coated layer was cleaved by the swelling force.The cleavage, occurred preferably on the weakest part of coating film, ie., the edge of the tablet, and the tablet was expanded longitudinally.In general, conventional gel matrix tablets (non-coated tablet) swell spherically and drugs are released from the spherical surface of the tablet.However, in the present novel gel matrix tablet coated with the water-insoluble material, the drug was released predominantly from the gel layer exposed on the side of tablet after the cleavage of the film, showing a typical zero-order release.The zero-order drug release may be attributable to this unique morphol.We call this system "Cho-chin" tablet, because the appearance of the tablet after the swelling resembled the "Co-chin" tablet, because the appearance of the tablet after the swelling resembled the "Cho-chin(Japanese Lantern)".On the basis of data studied for various oral dosage forms using the Cho-chin system, we decided to develop a generic drug for Adalat-CR tablet, because the drug release characteristic of the Cho-chin system was really similar to that of Adalat.For the development of this generic drug, the Cho-chin tablet was used as a core, which was further coated with a film containing the drug to adjust or sustain the drug release rate.We have succeeded to develop the generic drug of Adalat. utilizing the Cho-chin release system.In this report, we will introduce the developing processes of the once-a-day nifedipine sustained release tablet using our Cho-chin tablet technique.