Formulation Optimization of a Combined Mangosteen and Red Dragon Fruit Peel Extract Gel with Varying Carbopol 940 Concentrations

Abstract

One potential approach to enhance the benefits of mangosteen peel (Garcinia mangostana L.) and red dragon fruit peel (Hylocereus polyrhizus) is by formulating them into a gel dosage form. Carbopol 940 is a commonly used gelling agent, and its concentration must be carefully optimized as it significantly affects the gel’s physical characteristics and the absorption of active compounds through the skin. This study aimed to optimize and evaluate the physical properties of a gel formulation containing a combination of ethanolic extracts of mangosteen peel and red dragon fruit peel using varying concentrations of Carbopol 940 as the gelling agent. The experimental design employed three Carbopol 940 concentrations, 1%, 1.5%, and 2%, and the prepared gels were evaluated for organoleptic characteristics, homogeneity, adhesion, spreadability, pH, and viscosity. The results showed that increasing the concentration of Carbopol 940 led to higher viscosity and adhesion but reduced spreadability, resulting in a thicker gel consistency. Overall, the most optimal formulation was Formula 2, containing 1.5% Carbopol 940, as it met the required physical properties for a stable and well-balanced gel preparation.