Controlled Release of a Digestive Enzyme from a Swellable Semi-interpenetrating Polymer Network (IPN)

A novel interpenetrating polymer network (IPN) of poly(ethylene glycol), poly(vinyl alcohol) and poly(acrylamide) was prepared and its potential for sorption and delivery of diastase, a digestive enzyme, was evaluated. The effects of experimental parameters such as varying chemical composition of the IPN, percent loading of diastase, pH and temperature of the release medium and molecular weight of PEG were investigated on the release dynamics of the diastase. On the basis of Fick's equation the diffusional exponent (n) and diffusion constants (D) were evaluated for different IPN compositions. From the kinetic parameters data, an attempt was made to explore the nature of the mechanism of the release process of diastase. The IPNs were characterized by IR analysis and examined for zero-order release behavior of loaded enzyme.