CASEIN MICROBEADS AS A CONTROLLED PARENTERAL DRUG-DELIVERY SYSTEM

The formulation of a novel controlled release Parenteral dosage form w as the goal of this study. Microbeads of crosslinked casein containing Diethylstilboestrol (DEST), as a model drug, have been prepared using emulsion polymerization technique. The effect of different concentrat ions of Glutaraldehyde, as a cross linking agent, on particle size, pa rticle size distribution, shape of microbeads, drug content as well as the rate of drug release from the microbeads were studied. Spherical microbeads with low particle size distribution and high drug load were obtained as glutaraldehyde concentration increased. Furthermore, the release rate from the microbeads were decreasing with the increase of the concentration of the cross linking: agent. The effect of pH of cas ein solution as well as the amount of added drug on the characteristic s of the microbeads were also investigated. The biodegradability of ca sein microbeads prepared at glutaraldehyde concentration 2.37% were te sted in alpha-chymotrypsin solution. The microbeads showed a distinct signs of biodegradation within few days of incubation. No signs of adv erse effect were noticed when drug free casein microbeads were injecte d intraprotenially in mice. It was concluded that casein microbeads co uld be considered as a good candidate for the preparation of a dependa ble parenteral time release dosage form.