Determination of azelaic acid in pharmaceuticals and cosmetics by RP-HPLC after pre-column derivatization.

This paper reports a RP-HPLC method for the determination in topics of azelaic acid, a keratolytic and anti-comedogenic agent widely used in the treatment of all types of acne. A derivatization step was needed prior to chromatographic analysis because the analyte is lacking in chromophore. A sample clean-up procedure by solid-phase extraction was also developed to analyse azelaic acid in complex matrices, such as pharmaceutical and cosmetic formulations.