Examination of the optical purity of voriconazole on the brush-type stationary phase

The purpose of this research is to develop an HPLC method for determining the content of voriconazole enantiomers in powder for solution for infusion. Chromatographic analysis was conducted using a brush-type (Pirkle-type) stationary phase with isocratic elution. The mobile phase comprised a triethylamine-formate buffer system at pH 5.0/methanol/acetonitrile in an 80/15/5 (v/v/v) ratio, flowing at 1.0 mL/min. The temperature of the column was maintained at 30°C, and UV detection was carried out at 256 nm. The method was validated in accordance with ICH guidelines. After the selectivity was confirmed, a satisfactory resolution of the voriconazole enantiomers in the powder for solution for infusion was obtained. Order of the elution of the enantiomers was verified by comparing the retention times of the enantiomers in the sample with the corresponding standard of pure voriconazole isomer (impurity D). Linearity for voriconazole impurity D was assessed within a concentration range from 0.600 µg/mL to 1.500 µg/mL (correlation coefficient > 0.9999). Method precision was confirmed through intra-assay precision and inter-assay precision (RSD < 2%). The accuracy of the method was tested by analyzing three different concentrations, with analytical yields ranging from 93.75% to 102.27%. The validated method proved to be suitable for routine analysis in testing optical purity of voriconazole powder for solution for infusion.