Microemulsion technology: Nanoparticle-based emulsion as a sustainable natural product formulation

Natural products refer to chemicals or compounds from living creatures occurring naturally in the environment. Natural commodities, such as spices, herbs, and medical remedies, are often used as additions. Natural products have many advantages, such as their environmentally sustainable nature, compatibility with the skin, affordability, and widespread availability. Nevertheless, developing natural products has several challenges, such as limited options for ingredients, functional limitations of natural substances, considerations about stability and preservation, consumer perceptions and expectations, and the variability in the composition of natural products. Microemulsions are prevalent emulsions that incorporate nanoparticles. A microemulsion is a homogeneous, transparent liquid consisting of oil, water, and a surfactant, often combined with a cosurfactant. The use of microemulsions has been extensively observed in many chemical and pharmacological applications owing to their unique attributes, such as a significant interfacial area, little interfacial tension, and the ability to solubilise and deliver hydrophobic substances. Therefore, the present review paper aims to comprehensively analyse microemulsion technology and its applications as an environmentally friendly formulation for natural products. Here, we propose strategies and research on microemulsions to overcome problems in natural product formulations.