| Abstract: | The purpose of this study was to investigate the effect of varying drug load and concentration of a surfactant (sodium lauryl sulfate SLS]) on the release characteristics of a model peptide (bovine serum albumin BSA]), and study the net effects of the swelling properties of the hydrogel matrix poly(vinyl alcohol) (PVA)]. The PVA hydrogel was prepared by a freeze-thaw process in the absence of a chemical crosslinking agent. The effect of protein loading on drug release was examined at three levels (0.65, 1.3, and 2%), whereas the effect of SLS was studied at four levels (0, 0.07, 0.13, and 0.26%). The baseline time for reaching equilibrium swelling was 48 hr for the hydrogel containing 0.65% BSA, and the equilibrium swelling time decreased significantly as the protein load was increased to 2%. The net effect of increased BSA concentrations resulted in faster BSA dissolution from the hydrogel matrix. The equilibrium-swelling ratio decreased from 21 to 10% when SLS was added to the PVA solution, which resulted in a reduction in the extent of equilibrium swelling; however, the time to reach equilibrium swelling was increased. The investigation provided a mechanistic basis toward the development of a hydrogel formulation by altering the concentration of two fundamental components, i.e., drug and surfactant, within the delivery system. |
