Development and Evaluation of Injectable Hydrogel as a Controlled Drug Delivery System for Metformin

Aim: Chitosan-dialdehyde cellulose/DAC-based injectable hydrogel for controlled release of Metformin. 
Materials and Methods: Biomaterial-based injectable hydrogel was prepared by incorporating chitosan and dialdehyde cellulose. Dialdehyde cellulose (A cross-linker) was prepared by periodate oxidation method. The antidiabetic agent metformin was easily mixed with the chitosan and dialdehyde cellulose cross-linked solution, for the controlled drug delivery applications. The prepared injectable hydrogel showed the shear thinning property. 
Results: IR spectra confirmed the presence of cross-linked network between chitosan and dialdehyde cellulose. The physical appearance, injectability, pH, sol–gel phase transition, drug content, DSC, FTIR, and SEM studies were investigated. DSC and SEM studies revealed the degradation pattern and the topographical nature of prepared injectable hydrogel, respectively. The %drug release of metformin was found to be 87.25% prolonged for 84 h. The drug release pattern revealed the effective controlled drug delivery of metformin as compared to marketed tablet formulation. 
Conclusion: The study suggested that the controlled drug delivery system can be incorporated into the injectable hydrogel system; it would be more potential as compared to conventional controlled drug delivery system and preformed hydrogel system.