Development of standardized kaffir lime (Citrus hystrix) fruit peel extract as a gel for antioxidant and anti-acne

Abstract

Topical acne treatment using antibiotics causes an increase in the resistance of acne-causing bacteria. Using natural ingredients is an effort to avoid resistance, such as kaffir lime fruit peel which contains antibacterial substances, namely alkaloids, flavonoids, and tannins. This study aims to determine the effect of increasing the concentration of condensed extract of kaffir lime fruit peel in gel dosage form on physical quality (pH value, viscosity, dispersion) and effectiveness as an antioxidant and anti-acne. The condensed extract was obtained by maceration with 95% ethanol and then standardization of specific and non-specific extracts was carried out. The dosage form chosen is hydrophilic gel. The concentrations of the condensed kaffir lime fruit peel extract used in the gel are F1 (10%), F2 (15%), and F3 (20%). The gel preparation was tested for physical quality and effectiveness, consisting of antioxidant activity (IC50) using the DPPH method and antibacterial activity against Cutibacterium acnes using the diffusion method. Experimental data between batches and between formulas were analyzed using the One-Way ANOVA statistical method. If there is a significant difference in statistical analysis between formulas, then the test is continued using the Tukey post-hoc test method. The experimental results showed that increasing the concentration of kaffir lime fruit peel extract (Citrus hystrix) caused a decrease in pH and viscosity values as well as an increase in the ability to spread the gel preparation. Increasing the extract concentration also causes an increase in the anti-acne effect with the largest inhibition zone (18.27 ± 0.306 mm), and effectiveness as an antioxidant with the smallest IC50 value (15.51 ± 0.15 mg/mL) in formula 3. It was concluded that the best antioxidant and anti-acne gel is the F3 formula with an extract concentration of 20%.