Direct determination of D-panthenol and salt of pantothenic acid in cosmetic and pharmaceutical preparations by differential pulse voltammetry

D-Panthenol (provitamin B-5) and salt of pantothenic acid are used in many cosmetic and pharmaceutical preparations for their skin emollient, regenerating and hair conditioning properties. The cathodic reduction of D-panthenol and salt of pantothenic acid had been studied by differential pulse voltammetry (DPV) at carbon paste electrode (CPE) and metal oxides modified CPE in the presence of cationic surfactants (stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, dodecyltrimethylammonium chloride), anionic surfactants (sodium dodecyl sulfate, sodium dodecyl ether sulfate, sodium dodecylbenzenesulfonate) and non-ionic surfactants (TritonX-100, Span 60 and Tween 60) micelles. The peak potentials and peak currents have been found to be dependent on the character and concentration of the surfactant. The reduction potential of D-panthenol at a cobalt oxide modified CPE is shifted by 220 mV to more positive potential in the presence of the stearyltrimethylammonium chloride micelle. D-Panthenol and salt of pantothenic acid in commercial cosmetic and pharmaceutical preparations were determined by DPV using a cobalt oxide modified CPE in phosphate buffer (pH 6.08) solution. Comparison with results obtained from the spectrophotometry (SPM) shows good agreement. (C) 2001 Elsevier Science B.V. All rights reserved.