Development and validation of a stability-indicating HPLC method for determination of voriconazole and its related substances.

An isocratic reversed-phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the determination of voriconazole and its related substances. The drug substance was subjected to stress conditions of UV light, water hydrolysis, acid, base, oxidation, and deoxidization to observe the degradation products. The successful separation of voriconazole from its synthetic impurities and degradation products formed under stress conditions was achieved using an Agilent Zorbax SB-C18 (250mm x 4.6 mm i.d., 5 microm) column maintained at 25 degrees C with a mobile phase of a mixture of ammonium phosphate dibasic buffer (pH adjusted to 6.0 using diluted orthophosphoric acid; 50 mM)-acetonitrile (52:48, v/v). The mobile phase flow rate was 1.0 mL/min, and the detection wavelength was 250 nm. The stress sample solutions were assayed against the qualified reference standard of voriconazole and the mass balance in each case was close to 99.7%, confirming its stability-indication capacity. The developed HPLC method was validated with respect to linearity, accuracy, precision, specificity, and robustness. The developed HPLC method to determine the related substances and assay determination of voriconazole can be used to evaluate the quality of regular production samples. It can be also used to test the stability samples of voriconazole.