Development and validation of a spectrophotometric method for the quantification of kojic acid

Objetivo. Se desarrolló y validó un método para la cuantificación del ácido kójico en materias primas y en formulaciones por espectrofotometría ultravioleta. Material y métodos. Se utilizaron soluciones patrón de ácido kójico y se evaluaron parámetros de sensibilidad, robustez, exactitud, precisión y especificidad delo método. Resultados y Conclusiones. Los resultados mostraron que este método presenta linealidad entre 5 e 25 μg/ml, buena sensibilidad, robustez en cuanto a las variaciones en el tiempo de lectura y en la temperatura (pero no con variaciones de pH>7), exactitud y precisión. Sin embargo, la presencia de otra sustancia, que absorba en la misma longitud de onda que el ácido kójico (por ejemplo: el metilparaben), compromete la especificidad del método, pudiendo generar resultados erróneos.Objectives. A method for the quantification of kojic acid in bulk substances and preparations was developed and validated through ultraviolet spectrophotometry. Material and methods. Standardized solutions of kojic acid were used, from which the parameters of sensitivity, robustness, exactness, precision and specificity of the method were evaluated. Results and conclusions. The results obtained showed that this approach presents a linearity of between 5 and 25 μg/ ml, a high degree of sensitivity, robustness - evaluated in terms of variations in the times and temperatures at which readings were taken -(but not in pH>7 variations), as well as exactness and precision. However, the presence of any other substance that is absorbed within the same wavelength as kojic acid (for instance: methylparaben), can interfere with the specificity of the method, generating errors in the results obtained