Influence of Lanolin and White Soft Paraffin on the Determination of Vitamin a in Fats

Abstract Pharmaceutical interaction of the most frequently used substances with fats: lanolin, white soft paraffin and vitamin A palmitate was studied. The mixtures were examined by TLC with different ratios of lanolin and vitamin A palmitate, and white soft paraffin and vitamin A palmitate. Vitamin A in the mixtures was determined by the UV spectrophotometric method according to BP 93. It was established that the rise of lanolin concentration resulted in an increased apparent content of vitamin A in fats as a consequence of lanolin absorption at the wave length of maximum absorption of vitamin A. By an increase of white soft paraffin concentration, an apparent decreased in the content of vitamin A in fats was obtained. Therefore, the suggested UV spectrophotometric method for vitamin A determination has a limited application on fats with high content of lanolin and white soft paraffin.