Neem oil based nano-emulsion formulation by low energy phase inversion composition method: Characterization and antimicrobial activity

Abstract

This study aimed to prepare neem oil based nano-emulsion by using the phase inversion composition (PIC) method (low energy) followed by its characterization and assessment for antibacterial effectiveness. Nano-emulsion with droplet size below 200 nm was prepared at 27 °C by stabilizing neem oil-in-water with surfactant blend (Tween 80/Span 80) at a 1:1 vol ratio with hydrophilic-lipophilic balance (HLB) value of 10.7. The single-phase formulation of neem oil nano-emulsion was characterized for droplet size, zeta potential and viscosity. In contrast to raw neem oil and ampicillin antibiotic drug, nano-emulsion formulation showed improved antimicrobial activity against human pathogenic bacteria.