Formulation and In Vitro and In Vivo Assessment of Natural Emulgel Containing Lemongrass Essential Oil

This study aimed to develop a topical emulgel formulation from olive oil and lemongrass (LG) extracts and to evaluate its in vitro and in vivo (sensorial) properties in addition to its sun protection factor (SPF) value. The primary emulsion and the gel were prepared separately, and then they were levigated together to formulate the emulgel. The produced emulgel was evaluated for its physical appearance, pH, spreadability, and stability. The SPF value of emulgel was evaluated by applying the Mansur equation. Moreover, an in vivo sensorial assessment was conducted on the emulgel through a crossover study by including 20 volunteers. The results confirm good stability for emulgel formulations because there was no significant change in the pH value, no micelle inversion, or phase separation detected. The emulgel recorded a moderate SPF value (5.5) which can be useful for daily use, especially in tanned skin subjects. Moreover, the sensorial assessment of LG and blank emulgels showed a significant change in the cooling effect, odor, and smoothness and add some kind of moisture. In fact, there was a significant difference in overall properties between the two formulations where the p-value was less than 0.05. It is concluded the emulgel formulation containing LG and olive oil could be beneficial in terms of applicability and stability and can be easily formulated in pharmaceutical facilities. Besides, it would be useful for daily use because of the overall suitable properties, especially odor, feel, and SPF value.