Abstract
The conventional Gibbs' method for estimation of pyridoxine in cosmetic preparations has been improved in order to determine the contents of pyridoxine diacylate (PIN-DA). The sample from emulsified preparations, should be dissolved in a mixture of ethanol and chloroform (1 : 1) and if large amounts of interfering materials coexist, it must be pretreated by a chloroform extraction procedure. The sample solution thus obtained is then diluted with ethanol, the PINDA in it is reacted with 2,6-dibromoquinone chlorimide, and the absorbance at 650mμ is measured. This method was shown to be enough rapid and accurate for routine analysis of cosmetic samples.
