Preparation and characterization of konjac glucomannan–poly(acrylic acid) IPN hydrogels for controlled release

In this paper, we reported the synthesis and properties of interpenetrating polymer network (IPN) hydrogel systems designed for colon targeted drug delivery. The gels were composed of konjac glucomannan (KGM) and cross-linked poly(acrylic acid) (PAA) by N,N-methylene-bis-(acrylamide) (MBAAm). It was possible to modulate the swelling degree of the gels. And the swelling ratio has sensitive respondence to the environmental pH value variation. The degradation tests show that the hydrogels retain the enzymatic degradation character of KGM. In vitro release of model drug VB12 was studied in the presence of Cellulase E0240 in pH 7.4 phosphate buffer at 37 °C. The accumulative release percent of the model drug reached 85.6% after 48 h and the drug release was controlled by the swelling and the degradation of the hydrogels. The results indicated that the IPN hydrogels can be exploited as potential carriers for colon-specific drug delivery.