Preparation, stability and biological activity of essential oil-based nano emulsions: A comprehensive review

Abstract

The global concern of health and care has ever been on a rise. With the growing awareness of the negative impacts of chemicals on the human health, there have been extensive exploitations on aromatic and medicinal plants for a sustainable and bio-friendly ways of tackling various diseases. Essential oils (EOs) are innate constituents of aromatic and medicinal plants which are loaded with bioactive components and metabolites that are potent enough to treat various ailments. Even though, the scope of the application of EOs is still narrow due to constraints like high hydrophobicity, poor solubility in aqueous media, uncontrolled delivery action owing to their high volatility. Nano emulsion comes to the rescue of these discrepancies, with the EOs being encapsulated in it as droplets with nanometric scale diameter. In this review, we discuss some recent publications in the area of nano emulsions using EOs, detailed analysis of the mechanisms involved in their different methods of preparation, processing parameters that affect the size of droplets, stability. We also discuss the effect of the processing parameters of nano emulsions to their overall biological activities such as antimicrobial, insecticidal and acaricidal.

Keywords

• Nano emulsion
• Essential oil
• Antibacterial
• Antifungal
• Acaricidal