Evaluation of the Use of Different Oils and Emulsifiers in Oil-in-Water (O/W) Nanoemulsions

Introduction: Nanoemulsions (NEs) are a biphasic systems formed by two immiscible liquids: (1) oil-in-water or (2) water-in-oil emulsions. These systems exhibit unique physicochemical properties due to their small particle size, making them more versatile compared to other emulsion systems. Thus, this research aimed to produce and evaluate oil-in-water nanoemulsions. Methods: NE’s were prepared using Squalene, grape seed, and avocado oils, combined with soy lecithin or soy phosphatidylcholine as emulsifiers. The selection of oils considered both regulatory aspects and patent restrictions. Formulations were produced by microfluidization, and their physicochemical properties, such as particle size, polydispersity index, and zeta potential, were assessed at day one (D0) and day 7 (D7), under storage at 4°C, 25°C, and 40°C. objective: Thus, this research aimed to produce and evaluate O/W nanoemulsions. For this purpose, different oils, such as squalene oil, grape seed oil, and avocado oil, were combined with different emulsifiers, such as soy lecithin and soy phosphati-dylcholine. Results: The nanoemulsions produced with soy phosphatidylcholine and vegetable oils exhibited good preliminary stability, due to their small particle size. In contrast, formulations using soy lecithin as the emulsifier did not show favorable results, especially the one with grape seed oil, which showed a large particle diameter. However, none of these formulations exhibited cellular cytotoxicity. Discussion: Emulsifier selection had a strong impact on NEs characteristics, with Soy- PC producing smaller and more uniform particles compared to soy lecithin. All NEs showed good biocompatibility in fibroblasts, indicating their safety. Conclusion: Among the formulations, the one with phosphatidylcholine demonstrated a safer and more reliable stability profile, making it a promising candidate for application in the pharmaceutical and cosmetics industries.