NOVEL PREPARATION OF POLY(VINYL ALCOHOL) MICROPARTICLES WITHOUT CROSS-LINKING AGENT FOR CONTROLLED DRUG-DELIVERY OF PROTEINS

Poly (vinyl alcohol) microparticles were prepared by a novel freezing-thawing process in the absence of a crosslinking agent. An aqueous PVA solution was dispersed in com oil to which 1.25 wt% sodium lauryl sulfate was added. The system was agitated and the ensuing suspended droplets of PVA solution were solidified by a cyclic freezing-thawing process. Key parameters of the process were the PVA to com oil ratio, amount of surfactant added, agitation speed, number of freeze cycles, temperatures of freezing and thawing, and presence of additional components. The particles were then loaded with bovine serum albumin by an absorption technique and release studies were performed in vitro.