Stability comparison of two dermal emulsions containing Hippophae Rhamnoides L. oil

Two formulations of multiple emulsion (ME-1 & ME-2) containing Hipophae rhamnoides L. oil were prepared. Along with emulsifiers (Abil EM 90, Synperonic F127), Magnesium and Zinc were used as stabilizer in ME-1 and ME-2 respectively. Both formulations were prepared using Two-Step Method and after preparation ME-1 and ME-2 were stored at different storage conditions i.e., 4°C, 25°C, 40°C, 40°C+ 75% RH for four weeks for stability evaluation. At 4°C ME-1 and ME-2 showed phase inversion and were excluded from further stability evaluation. While ME-1 and ME-2 both were stable at 25°C for a period of four weeks as no color change, phase separation and liquefaction occurred. ME-1 and ME-2 at 40°C, 40°C+ 75% RH exhibited change in color, liquefaction and phase separation. The decrease in viscosity and globule size whereas increase in electrical conductivity and pH were observed at 40°C, 40°C+ 75% RH for a period of four weeks. Multiple emulsion from Hippophae rhamnoide L. oil are unstable at refrigeration and high temperature conditions. These formulations must be placed at room temperature to increase their shelf life.