Formulation and Evaluation of pH Sensitive Sustained Release Hydrogel of Methotrexate

Methods: Chitosan/glyceryl monooleate (C/GMO) solution was prepared in 0.33 M citric acid with gentle stirring. The weighed quantity of Drug and Chitosan in the required concentration was stirred with an appropriate quantity of 0.33 M Citric acid for 3 hours. Further, this solution was cooled to 4 o C. Then, to this cooled Chitosan and Drug solution, the desired amount of Glycerol Monooleate was added dropwise with constant stirring to obtain a clear homogenous system. Moreover, it was filtered by membrane filtration using the cellulose membrane. Finally, the prepared pH sensitive formulations were sterilized by autoclaving.