EXPLORING THE PHYSICOCHEMICAL AND ANTIMICROBIAL PROPERTIES OF AVOCADO PEAR OIL IN TOPICAL PHARMACEUTICAL FORMULATIONS

Abstract Avocado pear (Persea Americana mill) is a nutrient-rich, creamy textured, distinctive flavoured fruit with a high oil content, making it a valuable source of lipid-soluble bioactive compounds with diverse technological applications. In this study, we extracted oil from the mesocarp (flesh) of edible avocado pear using the mechanical extraction method and evaluated its physicochemical properties in comparison to commercial olive oil (OL). Parameters assessed included oil yield, pH, refractive index, specific gravity, relative viscosity, density, iodine value, saponification value, acid value, and free fatty acid composition. The extracted avocado oil (AV) was utilized in the formulation of benzoic acid and benzoic acid-ciprofloxacin hydrochloride ointments, which were assessed for antifungal efficacy. The extracted AV exhibited significant resemblance (p<0.05) to olive oil in terms of oil yield (27.5%), pH (AV:7.40; OL:7.8), iodine value (AV:0.04; OL:0.005 mg/KOH/g), acid value (AV:0.75; OL:0.65 mg KOH/g), and density (AV:1.21122; OL:1.00526 g/cm³), with no statistically significant differences (p>0.05). However, relative viscosity (AV:88.82; OL:57.53 cSt), saponification value (AV:106.17; OL:187.08 mg/KOH/g), and free fatty acid composition, particularly oleic (AV:0.28%; OL:0.62%) and linoleic acids (AV:0.41%; OL:0.27%), exhibited significant variation (p<0.05). All the benzoic acid formulations prepared with avocado oil demonstrated greater inhibitory activity against Aspergillus niger (An) compared to Candida albicans (Ca). The benzoic acid–ciprofloxacin formulation containing avocado oil, also demonstrated enhanced inhibitory activity against Aspergillus niger (33.10 mm) and Candida albicans (21.00 mm) compared to the olive oil-based formulation (An:27.57mm; Ca:22.50mm) and the control (An:25.75 mm, Ca:18.00 mm). Overall findings indicate that avocado oil exhibits physicochemical and antimicrobial properties comparable to those of olive oil, reinforcing its potential as a natural excipient in topical antimicrobial formulations as well as in other pharmaceutical, cosmetic, and industrial applications. Keywords: Avocado pear oil, physicochemical properties, olive oil, antimicrobial activity, topical preparation