Effect of Cholesterol and Different Solvents on Particle Size, Zeta Potential and Drug Release of Eucalyptus Oil Phytosome

Background: Herbal extracts show poor absorption and bioavailability but their complex with phospholipids i.e., phytosome improves this major problem. Aim: The aim of research was to examine the effect of cholesterol and different organic solvents on particle size and zeta potential of eucalyptus oil phytosome. Materials and Methods: Totally six batches of phytosomes were prepared using three solvents chloroform, dichloromethane, acetone, with and without addition of cholesterol. Phytosome were evaluated for yield, FTIR, partial size and zeta potential, drug entrapment and drug release, drug release kinetics and stability studies. Results: The yield, density refractive index and maximum absorbance (λ_max) of eucalyptus oil was found to be 1.65±0.74%, 0.9928 g/cm³ (24.2°C), 1.3613(24.6°C), and 297.733 nm respectively. There was no drug excipient interaction. The yield varied from 85.14±0.74 to 87.14±0.74%, particle size varied from 71.76±0.63 to 197.36±0.53 nm, zeta potential varied from 15.3±0.27 to-28.2±0.26 mV and entrapment efficiency varied from 57.45±0.35 to 67.34±0.52 respectively. The in vitro drug release varied from 87.26±0.63 to 71.35±0.63% up to 300 min (5 hr) and batch-A was selected as best formulation that showed Peppas Korsmeyer as the best fit model with R2 value 0.9422 and mechanism of drug release was Fickian Diffusion (Higuchi Matrix). The stability studies showed 99.14±0.25 to 99.55±0.52% drug content on 28^th day. Conclusion: The particle size of phytosomes was increased on addition of cholesterol. The acetone showed the smallest particle size and chloroform showed the biggest particle size that indicated that molecule diameter and molecular weight affects the solubility and assembly of phospholipid/ cholesterol in solvent in order to prepare particulate drug delivery system