ABSTRACT

The objective of the present study was to develop nano range liposomal formulation for cancer therapy and optimize the formulation by response surface method, i.e. 3² factorial design, in order to minimize more efforts, time and material use when formulation like the liposomes are developed. Two independent variables, namely, the concentration of lipid (X¹) and the concentration of cholesterol (X²), were set at three different levels. High and low levels of each variable were coded as 1 and -1, respectively, and the mean value was coded as zero. The dependent variables for factorial batches measured as vesicle size (Y¹) was 61.5 to 72.3%, and % encapsulation efficiency (Y²) was found to be 127 to 240 nm. Stepwise regression analysis was used to find out the control factors that significantly affect response variables. The results were subjected to ANOVA and multiple regression analysis that led to equations describing the effect of independent variables on the selected responses. The level of significance selected was 5% (p<0.05). Contour plot and response surface plot were constructed & overlay plot was used to optimize the formulation by keeping the desired responses. The optimized formulation CL-10 has vesicle size of 132 nm & PDI value of 0.241. Zeta potential of formulation was -20.4, conforming the formulations stability. Vesicular morphology measured by SEM & TEM study indicates that the vesicle was spherical in nature. Stability study of optimized formulation was carried out for 6 months as per ICH guidelines at 4⁰C and 37⁰C and indicates no significant changes in parameters like % drug release, vesicle size, % EE supported by student t test (p=0.05).