Herbal shower gel containing extracts of Momordica Charantia L. fruit and Houttuynia Cordata leaf: Formulation optimisation and anti-inflammatory evaluation

Momordica charantia and Houttuynia cordata are medicinal plants with well-documented anti-inflammatory properties, making them promising candidates for dermatological formulations. This study developed a therapeutic shower gel incorporating M. charantia fruit extract (3%) and H. cordata leaf extract (2%), and it established key quality-control parameters, including organoleptic properties, identification, in vitro anti-inflammatory activity, microbial and heavy metal limits, and irritation potential assessed via the Hen’s Egg Test on the Chorioallantoic Membrane assay (HET-CAM). A full factorial design was used to optimise the surfactant system across 12 formulations, resulting in an optimised product with appropriate viscosity, foam characteristics, and cleansing performance. The formulation exhibited a viscosity foamability of 238.56 ± 2.01 mL, foam stability of 99.26 ± 0.52%, and a dirt dispersibility score of 0.33 ± 0.00. The formulation exhibited measurable anti-inflammatory activity in the protein denaturation assay (IC50 ≈ 385 μg/mL) and did not show any irritation potential according to the HET-CAM. These findings indicate that the developed herbal shower gel is a safe, plant-derived cleansing product with promising anti-inflammatory skin potential. Further in vivo studies and clinical studies are recommended to verify the product’s therapeutic relevance. GRAPHICAL ABSTRACT