Formulation, Optimization and Evaluation of Herbal Hydrogel Containing Manilkara zapota Leaf Extract

The current study focused on creating, improving, and assessing a herbal hydrogel that contains Manilkara zapota leaf extract for topical use. The leaves of Manilkara zapota underwent Soxhlet extraction using a hydroethanolic solvent. We then screened the extract for various plant compounds. Preliminary phytochemical analysis confirmed the presence of flavonoids, tannins, phenolics, terpenoids, glycosides, alkaloids, and saponins, which suggests the plant extract has antioxidant properties. We prepared herbal hydrogel formulations using Carbopol 940 as a gelling agent. Propylene glycol served as both a co-solvent and a penetration enhancer. We optimized the formulations using Design-Expert® software, considering Carbopol 940 and propylene glycol concentrations as independent variables. We chose viscosity, spreadability, and pH as dependent responses. The prepared formulations were assessed for physicochemical properties such as appearance, pH, viscosity, spreadability, extrudability, washability, homogeneity, and stability. The formulations showed satisfactory physical traits, including smooth consistency, good homogeneity, acceptable pH, and suitable spreadability for topical application. The viscosity increased with higher concentrations of Carbopol 940, while spreadability decreased accordingly. The optimized formulation had a viscosity of 20150 cP, a spreadability of 6.7 g·cm/sec, and a pH of 6.1. This formulation demonstrated favorable physicochemical properties and maintained stability throughout the study. The close match between predicted and experimental values confirmed the reliability of the optimization. The study suggests that Manilkara zapota leaf extract can be effectively included in a Carbopol-based hydrogel system. It may represent a promising herbal topical formulation for antioxidant uses. However, additional pharmacological and clinical research is necessary to confirm its therapeutic effectiveness and long-term stability.