A simple, sensitive HPLC-PDA method for the quantification of itraconazole and hydroxy itraconazole in human serum: a reference laboratory experience

A chromatographic method (high-performance liquid chromatography/photodiode array detection) for the simultaneous determination of itraconazole and its mayor metabolite, hydroxy itraconazole, was developed. The validation data demonstrated acceptable values for linearity (dynamic range between 0.25–16 μg/mL for hydroxy itraconazole, 0.125–4 μg/mL for itraconazole), precision (Coefficient of Variation, 2.23–4.28% and 1.61–9.52% respectively), accuracy (Relative Error, −2.89 to −17.26% and −3.11 to 14.44%), selectivity, sensitivity (Lower limit of Quantification, 0.125 and 0.25 μg/mL), and recovery (97.30–105.82%) for both compounds. Its clinical suitability was also investigated in 104 trough human serum samples. The assay resulted to be rapid, sensitive, and simple for simultaneously quantification of these azole compounds in serum samples and should make a positive contribution to optimize therapies on an individual basis.