High performance liquid chromatographic separation of undeclared corticosteroids in topical herbal products

The aim of this work was to separate and to identify undeclared corticosteroids in topical herbal products. While most topical herbal products are safe, some products have been found to contain undeclared corticosteroids and represent a health risk [1]. In this study, we developed a simple reversed-phase HPLC-UV/Vis method for studying undeclared corticosteroids in topical herbal products [2]. Methods: Different herbal products were spiked with a mixture of four corticosteroids (fluocinolone acetonide, clobetasol propionate, betamethasone dipropionate and beclometasone dipropionate). Spiked samples were analysed using a Shimadzu LC10-Avp system, equipped with a UV-Vis detector, an auto-injector (20µL) and a Zorbax Eclipse XDB-C18 column (250 X 4.6mm, 5µm), at 30^oC and 1.0 mLmin^-1 flow rate. In each case, samples were extracted two times with ethanol and filtered (0.45µm) ready for injection. Results: Under these HPLC conditions, the resolution (Rs) of the mixture of corticosteroids was satisfactory (Rs ≥1.5). Retention times of fluocinolone acetonide, clobetasol propionate, betamethasone dipropionate and beclometasone dipropionate were 4.12, 13.97, 16.42 and 20.84min, respectively. In spiked samples, the peaks of the corticosteroids were separated from peaks of interfering substances like a matrix of cream/ointment or different herbal compounds. Conclusions: From these data, this method appears to be a valid and useful procedure for undeclared corticosteroids in topical herbal products. The established HPLC-UV/Vis method was suitable for rapid investigation of corticosteroids in topical herbal products.

References: 1. Ali, S.L. (2000) Pharm Chem J 34:31–32.

2. Gorog, S. (2004) Anal Sci 20:767–782.

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