Method validation for the quantification of fluconazole and its organic impurities in raw material using high-performance liquid chromatography

Introduction. The real laboratory conditions of each country, including climate, can affect the method’s efficiency in analyzing a pharmacological substance. Thus, it is necessary to validate the process according to the corresponding guidelines and optimize it to ensure success and confidence in the results. Objective. The objective was to validate a methodology for fluconazole and its organic impurities quantification in raw material using high-performance liquid chromatography, with a diode array detector, under tropical climate conditions, and complying with all regulatory requirements. Materials and methods. We performed pre-validation tests of the method consisting of system adequacy, filters study, quantification limit, absence of systematic error, forced degradation studies, and solutions stability. In addition, we validated the specificity, linearity, accuracy, precision, and robustness of the system. Results. Separation of the degradation products from the analyte peaks allowed the achievement of the method’s spectral purity. The solution’s stability was not affected during the evaluated time (24 hours) at room temperature and under refrigeration. Linearity resulted in correlation coefficients greater than or equal to 0.999 for the evaluation and greater than or equal to 0.997 for impurities. We obtained a fluconazole recovery varying from 98 to 102% with an accuracy between 80 to 120% for impurities detection. The repeatability and reproducibility factor did not exceed a relative standard deviation of 2.0% for the evaluation and of 5.0% for the impurities, demonstrating the adequate robustness of the method. In addition, a short analysis execution time allowed the quick determination of the raw material quality. Conclusion. We demonstrated that the fluconazole quantification method validated by high-performance liquid chromatography is sufficiently selective, precise, exact, linear, and robust to generate accurate analytical results under real conditions, including the tropical climate of Colombia.