Comparative Evaluation of the Physicochemical, Antimicrobial and Stability profile of Olive oil, Almond oil and Coconut oil-based Emulgels

The stratum corneum limits the dermal delivery of bioactive carrier oils such as almond oil, olive oil, and coconut oil, resulting in therapeutic failure. These oils could be formulated as emulgels to improve their penetration through the skin. To our knowledge, the properties of almond oil, coconut oil, and olive oil emulgels have never been compared. This work aims to formulate olive oil, almond oil, and coconut oil-based emulgels and evaluate their physicochemical, antimicrobial, and stability profile, for potential topical drug delivery. Nine emulgels, which differed in terms of the type and concentration of the carrier oil, were prepared using the spontaneous emulsification method. Their organoleptic properties, pH, viscosity, spreadability, antimicrobial activity, and accelerated and real-time stability profiles were evaluated using standard protocols. The emulgels exhibited acceptable organoleptic properties; pH values (5.2 to 5.7); spreadability (1-1.4 cm); and viscosity at 30 rpm: almond oil emulgels (384-794 cP); coconut oil emulgels (370-3620 cP); olive oil emulgels (798-9697 cP). The emulgels exhibited shear thinning behaviour; carrier oil concentration-dependent viscosity profile; and satisfactory accelerated and real-time stability profile. Formulations containing low concentrations of the carrier oil inhibited the growth of only E. coli (zone of inhibition: 7-10 mm) while those containing higher oil concentrations supported the proliferation of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Gardnerella vaginalis. Olive oil emulgels were the most promising formulations based on their properties. Also, the physicochemical and antimicrobial profiles of emulgels are dependent on the type and concentration of their constituent carrier oil.