Formulation and Evaluation of a Guava Leaf (Psidium guajava L.) Extract-Based Soap Bar as a Cleanser

Abstract

The cosmetic industry is rapidly developing, with a focus on safer and environmentally friendly formulations. Soap bars, which are widely used as skin-cleansing products, are increasingly being innovatively formulated using natural ingredients that provide additional benefits for the skin. Guava leaves (Psidium guajava L.), which contain flavonoids, tannins, and phenolic compounds, exhibit antioxidant, anti-inflammatory, and antibacterial properties, making them promising ingredients for cosmetic formulations. This study aimed to formulate and evaluate a guava leaf extract-based soap bar as a skin cleanser with antioxidant properties. An experimental method was employed to develop soap bars containing guava leaf extract through the saponification of virgin coconut oil (VCO), stearic acid, glycerin, and sodium hydroxide (NaOH), combined with guava leaf extract. The evaluations included physical appearance, pH, foam stability, and antioxidant activity using the DPPH assay. The resulting soap bars exhibited stable physical characteristics, an appropriate pH range (6–7), good foam stability, and significant antioxidant activity, with a DPPH inhibition percentage exceeding 70%. These findings suggest that guava leaf extract-based soap bars not only function effectively as cleansers but also provide additional protection against oxidative stress, supporting their potential as natural and functional skincare products.