STABILITY TEST OF 96% ETHANOL EXTRACT CREAM FROM STAR FRUIT LEAVES (Averrhoa bilimbi L.) WITH VARYING GLYCERIN CONCENTRATIONS

Abstract

Background: Bilimbi leaves (Averrhoa bilimbi L.) contain secondary metabolites that have potential as antioxidants. The development of cream preparations requires evaluation of physical stability, Glycerine as a humectant plays a role in influencing the physical stability of the preparation. Purpose: This study aimed to evaluate the effect of varying glycerine concentrations on the physical stability of 96% ethanol extract creams from starfruit leaves. Method: The extract was obtained by maceration using 96% ethanol and formulated into three cream formulations with glycerine concentrations of 10%, 15%, and 20%. Accelerated stability testing was conducted using the cycling test method for 6 cycles (12 days). Qualitative analysis included the identification of secondary metabolite compounds using thin-layer chromatography (TLC) as well as descriptive evaluation of organoleptic properties, homogeneity, and cream type. Quantitative analysis included pH, spreadability, adhesion, and viscosity tests, which were statistically analysed using the One Way ANOVA test if the data were normally distributed and homogeneous (p ≥ 0.05), while data that did not meet the requirements were analysed using the Kruskal–Wallis and Mann–Whitney tests. Results: Starfruit leaf extract was found to contain flavonoids, saponins, alkaloids, and tannins. All cream formulations showed good physical stability with pH suitable for skin, spreadability and adhesion meeting requirements, viscosity in accordance with SNI standards, and an oil-in-water (O/W) type. Conclusion: The 96% ethanol extract cream of starfruit leaves with varying glycerin concentrations showed good organoleptic characteristics, was homogeneous, had an oil-in-water (O/W) type, and met the requirements for pH, viscosity, spreadability, and adhesion before and after stability testing in all formulations. Varying glycerin concentrations affected the physical stability of the preparation. Formulation III with a glycerin concentration variation of 20% showed more optimal and stable physical stability compared to other formulations.