Zero-order Release of Metformin in Polyacrylamide Hydrogel

Water-soluble polymers with a three-dimensional crosslinked network structure, known as a hydrogel, has widespread applications in clinical and experimental medicine as drug carriers. Upon entering the targeted area for treatment, hydrogel loaded with drugs releases them through both diffusion and self-degradation mechanisms. In this study, the drug release process in polyacrylamide hydrogel uniformly loaded with metformin hydrochloride is investigated. To achieve a uniform drug release rate from the hydrogel, we establish a statistical model of drug release from polyacrylamide hydrogel using response surface methodology based on experimental design technique. The established statistical model can predict drug release behavior at a low cost within the design domain. The relationship between initial drug concentration and drug release rate in metformin-loaded polyacrylamide hydrogel has been investigated. A zero-order drug release effect in hydrogels is achieved through an optimized design of the initial distribution of drug concentration of a five-layered drug-containing hydrogel. This study has significant implications for the realization of drug molecule transport and sustained release in vivo.