Synthesis of Biodegradable Gum ghatti Based Poly(methacrylic acid-aniline) Conducting IPN Hydrogel for Controlled Release of Amoxicillin Trihydrate

Gum ghatti-graft-poly(methacrylic acid-aniline) interpenetrating network (IPN) hydrogel was prepared by a two-step aqueous polymerization method. First, poly(methacrylic acid) (poly(MAA)) chains were graft co-polymerized onto a Gum ghatti (Gg) backbone via free radical polymerization. Different reaction conditions were optimized in order to incorporate maximum water uptake capacity of the synthesized hydrogel. The synthesized hydrogel network showed a pH-dependent swelling behavior. Second, aniline (ANI) monomer was penetrated through the preformed Gg-g-poly(MAA) network by simple oxidative polymerization method. The homogeneity and distribution of different ions of the cross-linked hydrogels were investigated by the time-of-flightsecondary-ion mass spectrometry chemical imaging technique, and a correlation analysis by color overlay and scatter plot technique. The resulting cross-linked hydrogels structure, morphology, and thermal behavior were investigated. Biodegradation studies of the cross-linked hydrogel samples were carried out by composting soil test for a period of 60 days. The evidence for biodegradability has been confirmed by carrying out the scanning electron microscopy technique. The release profiles of the hydrogel networks were investigated through amoxicillin trihydrate model drug under different pH conditions at 37 degrees C. Drug release through the Gg-g-poly(MAA) matrix was found to show non-Fickian behavior at pH 2.2 and 7.0, whereas, a Fickian mechanism was exhibited at pH 9.2. On the other hand, Gg-g-poly(MAA-IPN-ANI) matrix exhibited Fickian behavior at each pH media. The hydrogel networks showed less release in acidic and neutral media than in basic media, suggesting that hydrogels may be suitable drug carriers for colon specific controlled release of drug delivery in the lower gastrointestinal tract.