Preparation and characterization of gelatin-poly(methacrylic acid) interpenetrating polymeric network hydrogels as a ph-sensitive delivery system for glipizide
Department of Pharmaceutics, J. S. S. College of Pharmacy, Sri Shivarathreeshwara Nagar, Mysore-570 015, India
H G Shivakumar Department of Pharmaceutics, J. S. S. College of Pharmacy, Sri Shivarathreeshwara Nagar, Mysore-570 015 India E-mail: [email protected]
In the present study, interpenetrating polymeric network hydrogels of glipizide were prepared using gelatin and methacrylic acid. Methacrylic acid was polymerized using potassium persulfate. Methacrylic acid was crosslinked with methylene bisacrylamide and gelatin was crosslinked using glutaraldehyde. Four formulations were prepared by varying the concentrations of methacrylic acid, methylene bisacrylamide and glutaraldehyde. The amounts of gelatin and potassium persulfate were kept constant in all the formulations. The interpenetrating polymeric network hydrogels were characterized by fourier transform infrared analysis, differential scanning calorimetry and evaluated for swelling and deswelling properties, drug loading and in vitro drug release. All the formulations showed no interaction between drug and polymer as confirmed by fourier transform infrared analysis and differential scanning calorimetric studies. The interpenetrating polymeric network hydrogels swelled only in alkaline pH and swelling was minimal in acidic pH. It was found that as the concentration of cross-linking agents is increased, there is a decrease in swelling and, as the concentration of methacrylic acid is increased, there is an increase in swelling. The release data shows that, as the concentration of methacrylic acid was increased, swelling increased resulting in increased release of the drug.