Validation of a HPLC-UV method for the quantification of budesonide in skin layers

A simple and sensitive HPLC method for the quantification of budesonide in skin layers was developed and validated. Budesonide was extracted from stratum corneum, epidermis and dermis by means of a mixture of acetonitrile:water (recovery > 90%). Budesonide quantification was performed with a RP-C18 column using methanol and water mixture (69:31, v/v) as mobile phase, pumped at 0.8 ml/min. The absorbance was monitored at 254 nm. The method resulted to be selective, linear in the range 0.05-5 or 10 mu g/ml, precise and accurate. LLOQ resulted to be 0.05 mu g/ml. The developed method appeared to be appropriate for the quantification of budesonide in skin layers at the end of in vitro permeation experiments since the recovery of the applied dose was 97 +/- 1%, in line with requirement of the OECD guideline for the testing of the chemicals (Skin absorption: in vitro method).