Loading of Cefixime to pH sensitive chitosan based hydrogel and investigation of controlled release kinetics.

Chitosan (biopolymer) and polyvinyl pyrolidone (PVP) with aminopropyletriethoxy silane (cross linker) based hydrogels were prepared and tested for controlled drug release. The drug release and kinetics were studied as a function of pH. Formulations were characterized by Fourier Transform Infrared (FTIR) and Thermogravimetric (TGA) analysis and TAP 32 hydrogel formulation was the most stable and hydrogel samples showed promising antibacterial activity against E. coli strain. The maximum swelling (4386%) was observed for TAP 32 formulation in distilled water, which was decreased with the concentration of ions. The diffusion exponent (n) values of all hydrogel formulations were recorded to be <0.5, which is an indication of Quasi-Fickian diffusion. The maximum swelling was observed at pH 2 and decreased at higher pH. The pH sensitivity of hydrogels found to be promising for their use in drug delivery, which was tested for cefixime drug. Drug release of 81.6% was observed for the period of 12 h in a simulated gastric fluid (SGF). The values of R2 for zero order, first order, Higuchi, Hixson, Korsmeyer-Peppas and Baker-Lonsdale were 0.97, 0.9818, 0.99, 0.99, 0.88 and 0.80, respectively. The hydrogels based on chitosan and PVP revealed potential for controlled cefixime drug release in gastric pH medium.