Formulation Development of a Facial Cleansing Gel Containing Phyllanthus amarus Extract and Aloe vera Juice With Antioxidant Activity

Phyllanthus urinaria and Aloe vera have been traditionally used in Vietnamese medicine for their various pharmacological properties, including antioxidant activity. However, their combination in facial cleansing gel formulations has not been extensively studied. This study aimed to develop a facial cleansing gel containing extracts of Phyllanthus urinaria and Aloe vera with proven antioxidant effects. The plant materials were extracted and evaluated for antioxidant activity before incorporation into the gel formulation. The formulation was optimized by varying the concentrations of cocamidopropyl betaine and carbopol, with selection criteria based on sensory characteristics, foaming ability, dirt dispersion, pH, and viscosity. The final product was assessed for quality attributes, including irritation potential using the Hen’s Egg Test–Chorioallantoic Membrane (HET-CAM) assay and antioxidant activity using the DPPH radical scavenging method. The optimized formulation, containing 0.75% carbopol and 1% cocamidopropyl betaine, met the established quality criteria, exhibited a dirt dispersion and foaming ability of over 90%, viscosity within the range of 2000–4000 cP, and a pH of approximately 6. The formulation demonstrated no irritation potential and exhibited antioxidant activity with an IC50 value of 161.34 ± 3.82 μg/mL. This study successfully developed a natural facial cleansing gel containing Phyllanthus urinaria and Aloe vera extracts, contributing to the advancement of safe and effective natural skincare products.