Matrix Type Tablet Formulation for Controlled Release of Highly Water Soluble Drugs

Abstract

Matrix type formulations with dicalcium phosphate dihydrate (DCPD) using a polymeric binder (Eudragit RSPM®) to obtain controlled release of highly water soluble drugs has been investigated.

The drug, DCPD and Eudragit RSPM® were granulated using isopropyl alcohol with and without a plasticizer (Diethyl phthalate, DEP). Addition of Eudragit did not appear to affect the release profile. However, addition of a plasticizer had a significant effect on the rate of release. The release appears to follow first order kinetics and the rate constant decreased linearly with increasing DEP concentration.

A directly compressible mixture was also formulated by coating DCPD particles with DEP with and without Eudragit RSPM®.