Comparative Evaluation of Zingiber officinale Roscoe and Centella asiatica (L.) Urb Extracts: Chemical Characterization, Lotion Formulation, and Antibacterial Activity Against Staphylococcus epidermidis

Zingiber officinale Roscoe and Centella asiatica (L.) Urb are medicinal plants widely utilized in traditional medicine due to their diverse bioactive compounds and potential antibacterial properties. This study aimed to compare the chemical constituents, physicochemical characteristics of lotion formulations, and antibacterial activities of ethanolic extracts from Z. officinale Roscoe and C. Asiatica (L.) Urb against Staphylococcus epidermidis. The extracts were prepared by maceration using 96% ethanol and analyzed using gas chromatography–mass spectrometry (GC-MS). The obtained extracts were incorporated into oil-in-water (o/w) lotion formulations and evaluated for organoleptic properties, pH, and antibacterial activity using the agar well diffusion method. GC-MS analysis identified zingiberene (36.24%) as the predominant compound in Z. officinale extract, followed by β-sesquiphellandrene (13.22%), 2-butanone (11.63%), farnesene (7.21%), β-bisabolene (7.14%), and eucalyptol (1,8-cineole) (3.68%). In contrast, C. asiatica extract contained hexadecanoic acid (28.17%), 9,12,15-octadecatrienoic acid (27.88%), oxacycloheptadec-8-en-2-one (22.15%), and neophytadiene (10.15%). Both extracts were successfully formulated into homogeneous lotions with acceptable physicochemical properties, including yellow to yellowish appearance, uniform texture, pleasant odor, and pH values ranging from 7 to 8. The lotion formulations exhibited antibacterial activity against S. epidermidis, with inhibition zones ranging from 28 to 29 mm,while clindamycin as the positive control showed an inhibition zone of 35 mm. These findings demonstrate that Z. officinale and C. asiatica extracts possess promising antibacterial potential when incorporated into topical lotion formulations and may serve as candidates for the development of natural-based pharmaceutical and cosmetic products.