Development and Evaluation of a Nanoemulsion-Based Hydrogel from Moringa Leaves Extract: Standardization, Biological Activity, and Formulation

Moringa oleifera, known for its rich phytochemical profile, has garnered attention for its potential in skin health applications, particularly concerning antihyperpigmentation and anti-acne effects. The objective of this study investigated the antioxidant, antityrosinase, and antibacterial activities of standardized Moringa leaf extract (MLE) formulated into a nanoemulsion-based hydrogel for topical application. The ethanolic extract was prepared and standardized following the Indonesian Herbal Pharmacopoeia. The antioxidant, antityrosinase, and antibacterial properties of the extracts were assessed to confirm their biological efficacy. Ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) was used to characterize the chemical composition of the nanoemulsion, which was formulated using six different oil preparations. The nanoemulsion was characterized using several parameters, including percentage of transmittance, particle size, polydispersity index, and zeta potential. The stability of the nanoemulsion-based hydrogel was tested while paired and unpaired student t-tests were used for data analysis of hedonic test, with p <0.05 considered statistically significant. The MLE met the Indonesian standardization parameters and demonstrated antioxidant activity, with an IC₅₀ value of 0.21 mg/ml, which is more than twice the IC₅₀ value of vitamin C (0.096 mg/ml). The IC₅₀ value of MLE in the inhibitory tyrosinase assay was 9.394 mg/ml, which was higher than the IC₅₀ of kojic acid (0.096 mg/ml). MLE was also active against S. epidermidis and S. aureus but not against E. coli. The particle sizes of the nanoemulgel preparations ranged from 30.3 ± 0.47 nm to 74.4 ± 4.8 nm. Our study demonstrated that MLE, which contains flavonoids and polyphenols, possesses antioxidants, antityrosinase, and antibacterial activities. Furthermore, MLE has been successfully incorporated into a stable nanoemulsion-based hydrogel, potentially offering a novel therapeutic approach for skin care.