Essential oil of Eucalyptus citriodora: Physio-Chemical analysis, Formulation with Hand Sanitizer Gel and Antibacterial Activity

Background: The essential oil-bearing plants are extensively being used in traditional systems of medicine due to the occurrence of the diversity of phytochemical constituents. The emerging crisis of developing resistance to conventional drugs has increased public health awareness and reliance on natural compounds as safer alternatives.Methods: The essential oil extracted from Eucalyptus citriodora (Hook.) leaves was characterized for physicochemical attributes, formulated with hand sanitizer gel, tested for organoleptic parameters, and antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis.Results: E. citriodora essential oil (EEO) had a camphorous scent, and dark yellow coloration, while exhibiting 0.60% yield (v/w, 97% pure), 0.94 density, 1.47 refractive index, 11.10 viscosity, 0.92 specific gravity, 0.0-9.98º optical rotation, 11.20 acid number, 50.60 ester number, which satisfy the standards specified by ISO (The International Organization for Standardization). The chromatographic analysis of oil identified eucalyptol as the most abundant compound (80.08%) followed by α-terpinyl acetate, isopinocarveol, and globulol as the moderately abundant compounds (4.46-4.81%), while viridiflorol and terpinen-4-ol as less abundant compounds (3.06 and 2.69%, respectively). Formulated hand sanitizer with EEO exhibited physical and microbiological properties that were comparable with the market products. It also had a pleasant scent, was compatible with the skin, was easy to apply, and is acceptable to the users.Conclusion: The current study clearly shows that EEO could be utilized as a potential ingredient in alcohol-based gel hand sanitizer formulation for giving a pleasant smell, acceptable physical appearance and microbial quality parameters.