Development of novel hydrogels by functionalization of sterculia gum for use in anti-ulcer drug delivery

In view of the pharmacological importance of sterculia gum and drug delivery devices based on hydrogels, the present study is an attempt to synthesize sterculia gum and poly(AAm) based hydrogels by using N,N'-MBAAm as crosslinker and ammonium persulfate as initiator. The polymeric networks were characterized by SEMs, FTIR and swelling studies. The release dynamics of model anti-ulcer drug (ranitidine hydrochloride) from the hydrogels has been studied for the evaluation of the release mechanism and diffusion coefficients. The values of the diffusion exponent 'n' (0.43, 0.44 and 0.62) and gel characteristic constant 'k' (8.669 x 10(-2), 8.016 x 10(-2) and 2.964 x 10(-2)) have been obtained, respectively, in distilled water, pH 2.2 buffer and pH 7.4 buffer. The release of drug from the hydrogels occurred through Fickian diffusion mechanism in distilled water and in pH 2.2 buffer, and through non-Fickian diffusion mechanism in pH 7.4 buffers. (c) 2008 Elsevier Ltd. All rights reserved.