Bioactive Eucalyptus and Peppermint Oil Blend Microemulsion Preparation, Characterization and Evaluation

Background: Rhinitis is a prevalent condition affecting individuals of all age groups, resulting from factors such as cold, nasal infections, allergies, inflammation, and sinusitis. The diverse compositions of bioactive essential oils, containing many chemical components, hold significant promise in preventing and treating numerous human diseases. Certain herbs exhibit favorable physiological and medicinal values when administered individually or in combination with others. Both eucalyptus oil and peppermint oil have been traditionally used to alleviate nasal congestion. Aim: Considering the synergistic effects of bioactive oils, the present study aimed to develop nasal microemulsion systems using bioactive oils. Materials and Methods: The microemulsion was prepared with eucalyptus oil and peppermint oil based on the pseudo-ternary phase diagram with different ratios of surfactant and co-surfactant. The microemulsions were evaluated for pH, electrical conductivity, viscosity, optical transparency, droplet sizes and stability studies. Results: The microemulsion droplets were nano-sized and stable at different temperature conditions. The in vitro anti-inflammatory activity of the microemulsion was assessed by protein denaturation assay and showed a promising result compared to the standard drug. Conclusion: Eucalyptus oil and Peppermint oil blend microemulsion formulations could be an effective platform for nasal drug delivery system for the treatment of rhinitis