Investigation of the Effect of Gammaoryzanol Addition on the Properties of the Nanoliposomes by using Response Surface Methodology: Preparation, Characterization and Optimization

Liposomes are the most important lipid-based nanocarriers, which are used for encapsulation of both hydrophilic and hydrophobic active compounds. The aim of this study was to investigate the effect of Gammaoryzanol (GO) addition to lipid bilayers on characteristics of liposomes prepared by a modified ethanol injection method. The GO bearing nanoliposomes were prepared with different molar ratios of phosphatidylcholine (PC): GO. PC: GO molar ratio was concerned as the independent variable while particle size (PS), encapsulation efficiency percentage (EE%) and drug release over 24 h (D24h) were considered as the dependent variables. The variables were analyzed and optimized by employing response surface methodology (RSM). Also, graphical response surfaces and contour plots were drawn to understand the interaction effects of different variables. Finally, optimum levels of the variables were obtained from the optimization plots. The mean PS, EE% and D24h values of Celecoxib-loaded nanoliposomes were found to be 102.6 ± 9.5 nm, 67.6 ± 11.2% and 53.97 ± 9.6 %, respectively. The results indicated that both PC: GO and PC: Drug ratios are important variables contributing to PS and EE% of the nanoliposomes. However, just PC: GO had an effect on D24h (P<0.05). According to the findings, optimized formulation of Celecoxib nanoliposomes is associated with PC: GO and PC: Drug ratios of 4.6 and 3, which provides PS = 102 nm, EE% = 74.2% and D24h = 59.9 %. In conclusion, addition of GO and using ethanol injection method, with respect to optimization of the parameters by RSM technique, presents a simple, rapid and beneficial approache for preparation of nanoliposomes with optimum characteristics.