Formulation, Physical and Chemical Stability of [italics]Ocimum gratissimum[/italics] LLeaf Oil Nanoemulsion

[italics]Ocimum[/italics] [italics]gratissimum[/italics] L. leaf oil exhibited many pharmacological properties. This study aimed to formulate and evaluate the physical and chemical stability of [italics]O.[/italics] [italics]gratissimum[/italics] leaf oil nanoemulsion. [italics]O.[/italics] [italics]gratissimum[/italics] leaf oil was extracted by hydrodistillation. The major component of the essential oil eugenol, was analyzed by UV-Vis spectrophotometry. Nanoemulsions of [italics]O.[/italics] [italics]gratissimum[/italics] leaf oil were formulated using polysorbate 80, hyaluronic acid, poloxamer 188, and deionized water by phase inversion composition method. The hydrodynamic diameter, polydispersity index, and zeta potential value of [italics]O.[/italics] [italics]gratissimum[/italics] leaf oil nanoemulsion was evaluated by a dynamic light scattering technique. The %remaining of eugenol in the nanoemulsion was analyzed by UV-Vis spectrophotometry. The essential oil extracted from of [italics]O. gratissimum[/italics] leaf oil was a clear, pale yellow color. The %yield of the essential oil was 0.15 ± 0.03% v/w. The size of the nanoemulsion was less than 106 nm. The polydispersity index of the nanoemulsion was ranging from 0.303 - 0.586 and the zeta potential value of the nanoemulsion was closely to zero, depending on the formulation component. [italics]O. gratissimum[/italics] leaf oil at concentrations ranging from 0.002 - 0.012% v/v contained 35 - 41% of eugenol. The size of nanoemulsion was significantly decreased after storage at 4 °C, while significantly increased upon storage at 45 °C. The size of nanoemulsion stored at 30 °C did not significantly change. The %remaining of eugenol in the nanoemulsion was more than 90% after storage at 4 °C and 30 °C for 28 days. The percentage of eugenol remaining in the nanoemulsion stored at 45 °C was more than 85 - 90%, suggesting that the temperature affected the stability of eugenol in the nanoemulsion.