Investigations of epidermal growth factor in semisolid formulations

Three simple formulations, with various physicochemical characteristics, were designed as potential pharmaceutical bases for delivery of epidermal growth factor (EGF) to open wounds. The compatibility of EGF with formulation excipients and the release of EGF from each formulation were evaluated in vitro using a release cell apparatus. Samples were analyzed by competitive heterogeneous radioimmunoassay. The apparatus and procedures used in the study were validated to ensure EGF stability during the study, and to verify the absence of excipient interference with analytical procedure. Batches of Pluronic F-127 25% gel formulation and Carbopol gel formulation showed similar average EGF release rates of 17.12 and 16.55 micrograms/cm2/hr, respectively. A vanishing cream formulation similar to the commercial product Silvadene showed much slower release of 0.5 microgram/cm2/hr.