The objective of this study was to determine the best conditions to formulate solid lipid Nanoparticles using Glyceryl  monostearate as lipid matrix which has advantage to be biocompatible and easily degraded in vivo. Different formulation factors were studied including effect of viscosity, method of manufacture and homogenization speed. It was found that method of emulsion solvent injection technique produced smaller particles size than that of the hot homogenization technique for both Tween 20 and Tween 80. The effect of viscosity was prominent with high viscosity value obtained through use of 50 % glycerol as viscosity enhancer. According to homogenization speed, it was found that increasing homogenization speed from 6,000 rpm to 12,000 rpm produced smaller solid lipid nanoparticles with small polydispersity index and homogenous distribution of particle size distribution.