Novel interpenetrating polymer network mucoadhesive microspheres of locust bean gum and poly(vinyl alcohol) for the delivery of Famotidine

Novel interpenetrating polymer network (IPN) of locust bean gum (LBG) and poly vinyl alcohol (PVA) were prepared and crosslinked with glutaraldehyde (GA) to form mucoadhesive microspheres by emulsion cross-linking method to deliver model anti-ulcer drug, famotidine. Various formulations were prepared by changing the ratio of LBG: PVA, extent of cross-linking in order to optimize the formulation variables on drug encapsulation efficiency and release rate. FTIR spectroscopy was done to confirm the formation of interpenetrating network and the chemical stability of famotidine after penetration of microspheres. Microspheres formed were spherical with smooth surfaces as revealed by SEM and mean particle size as measured by optical microscopy ranged between 10.83±0.75μm to 21.13±0.74μm. Drug entrapment efficiency was ranges between 65.44±2.57% to 84.67±2.58%. Percentage mucoadhesion of the microspheres was found to be in the range between 63.33±2.57% to 86.66±3.65%. Equilibrium and dynamic swelling studies were performed in 0.1N HCl buffer solution of pH 1.2 and diffusion coefficients were calculated by considering the spherical geometry of the matrices. In vitro release studies were performed in pH 1.2 media. Release data indicated that a drug release which depends on the extent of cross-linking and the ratio of LBG: PVA present in the microsphere. The release data were fitted to an empirical equation to estimate the transport parameters, which indicated that the release follows Super Case II transport mechanism. Based on the results of in-vitro studies it was concluded that these IPN mucoadhesive microspheres provided oral controlled release of famotidine.