Effect of Light and Storage Time on Vitamin E in Pharmaceutical Products

Abstract

Vitamin E is an important oxidant for both plant and animal and a lipid soluble vitamin which occurs naturally in edible plant oils and able to be synthesized by oxygenic bacteria. Besides, cooking oils and edible oil containing seeds, human can intake vitamin E via pharmaceutical products. With simply spectral method, vitamin E contents in tablets were quantified easily during storage. Vitamin E levels in medical products sold on Vietnamese market varied among producers ranging from 15 mg up to about 360 mg/tablet. Vitamin E in eight selected products was degraded gradually with prolonged storage time but much more rapidly in scatter light exposure condition than in the dark. The more vitamin E in the tablets, the quicker degradation occurred. Tablets exposed to natural sun light or UV source depleted vitamin E significantly within 5 h, approximately 50% for both lighted conditions. There was a relatively high tight correlation $(R^2 = 0.8266)$ between tablet price and its vitamin E content. Customer should buy the higher price products rather than the cheaper ones to get sufficient amount of vitamin E. Pharmaceutical vitamin E products should be used up soon after being bought or kept away any light sources.