LINEAR EXTENDED-RELEASE OF A WATER-INSOLUBLE DRUG, CARBAMAZEPINE, FROM ERODIBLE MATRICES

The preparation and in vitro characterization of extended release erod ible hydrophilic matrices containing a water insoluble drug (carbamaze pine) are described. The matrices are obtained by tabletting mixtures of the drug with a water swellable polymer (cross-linked sodium carbox ymethylcellulose) and a water gelling polymer (hydroxypropylmethylcell ulose). These matrices appear to be subject, during in vitro tests, bo th to a gelation and to an erosion process and they are capable of rel easing the drug at a nearly constant rate, until almost the entire dru g content is released. The influence of the technological parameters o f the formulation (weight ratios of polymers used, compression forces, etc.) and of the gelation and erosion processes of the matrices durin g the in vitro tests, on drug release are investigated.