PREPARATION OF VITAMIN-E MICROEMULSION POSSESSING HIGH-RESISTANCE TO OXIDATION IN AIR

Vitamin E is widely used in pharmaceutical, food and cosmetic preparations. This paper discusses methods of preparing vitamin E emulsions by using polyoxyethylene mono-n-alkylether non-ionic surfactants. The amount of vitamin E dissolved in water was analyzed by turbidity and UV absorption measurements. The emulsion size was determined by laser light scattering. Microemulsions with small particle size and high resistance to oxidation in air can be obtained by solubilizing vitamin E in the non-ionic surfactant solutions, whereas solubilization in sodium dodecyl sulfate solutions results in emulsions having small size but not the stability against oxidation. Kinetics and mechanisms involved in the dissolution of vitamin E are discussed. It is suggested that a stable microemulsion can be obtained by proper matching of the molecular structures between the solubilizer and the solubilizate.