Simple detecting method of adrenocorticosteroid in external preparations - Combination of thin-layer chromatography and color reaction by blue tetrazolium

Mixtures of commercial external preparations of adrenocorticosteroid are widely used in the treatment of atopic dermatitis. Recently, an atopic dermatitis patient brought an ointment including unclear components. Therefore, we tried simple analysis to detect adrenocorticosteroid in external preparations. Commercial adrenocorticosteroid ointments were used as comparison. The separation analysis was performed by thin-layer chromatography (TLC). The spot from the unknown sample showed positive reaction to coloring reagent. As the spots from Myser® ointment and the unknown sample showed the same Rf value, it was suggested that the unknown sample was possible to include Myser® ointment. Among the coloring reagent used, alkaline blue tetrazolium reagent showed the highest detective sensitivity. Consequently, it is confirmed that the combination of TLC and the coloring test is useful for detection of the adrenocorticosteroids in the ointments.