Optimizing formulation of green tea extract-loaded chitosan nanogel

Green tea extract has many potent antioxidants known for their beneficial health effects. One such compound is epigallocatechin-3-gallate, which exhibits chemotherapeutic properties and can reduce cholesterol levels in blood. Since the topical delivery of drugs is difficult, nanogels have great potential due to their reduced particle size and structural properties. The present study investigated the impact of independent variables such as carbopol and triethanolamine (TEA) concentrations on nanogel pH, viscosity, and in vitro diffusion. All formulations were generated by Box-Behnken design and followed the nanoprecipitation technique to prepare nanogel. Formulations were tested for pH, homogeneity, spreadability, viscosity, drug content, particle size, zeta potential, and entrapment efficiency (EE) and characterized for surface morphology. The prepared chitosan nanoparticle designated F5 was seen to show an encapsulation efficiency of 94.11% with a practical yield of 94.41%. Also, after GTE loading, the nanogel formulation NG15 showed optimal drug content of 99.87%. Besides, the nanogel was also characterized based on F5 showing the best results. From surface plots, the varying effects of interacting parameters could be elucidated, and ANOVA studies showed that all designed models were significant with acceptable values for the statistical parameters. Conclusively, GTE-loaded nanogel seems to be robust and therefore could be used with a promising potential for topical drug delivery.