Comparative Study of Drug Release of Carvedilol Microparticles by Using Different Polymers

Microspheres/microparticles constitute an important part of drug delivery system by virtue of their small size and efficient carrier characteristics. These delivery systems offer numerous advantages compared to conventional dosage forms, which include improved efficacy, reduced toxicity, improved patient compliance and convenience. The objective of the present investigation is to design and evaluate controlled release tablets of carvedilol, which were prepared by solvent evaporation method by using different polymer (Ethyl cellulose, Cellulose acetate, Hydoxy Ethyl Cellulose).The in vitro release kinetics was carried out by fitting the release data to models representing zero-order, first-order, and Higuchi’s square root of time. It was found that all the formulations were best fit into Higuchi's square root release model. It confirmed that the drug is very slowly diffusing out of the polymer matrices and showing a much sustained release.