Development and validation of a UV spectrophotometric method for biowaiver studies in pyrazinamide tablets

Abstract

Context: For regulatory reasons, a biowaiver is characterized as the substitution or exemption of bioavailability and/or bioequivalence research with in vitro dissolution tests, according to the Biopharmaceutical Classification System (BCS). These studies need validated quantification methods to give reliable results. Aims: To develop and validate the UV spectrophotometric method for biowaiver studies in pyrazinamide tablets. Methods: The parameters for validation, such as specificity, linearity, range, accuracy, precision, stability of the analytical solution, filter test, limits of detection, and quantification, were assessed according to the standards set by the guidelines of the International Conference on Harmonization and the United States Pharmacopeia. The dissolution operating conditions were 900 mL of dissolution media at pH 1.2, 4.5, and 6.8, with the paddle method at 75 rpm and sampling times of 5, 10, 15, 20, and 30 minutes. Results: The wavelength of maximum absorbance was 268 nm for the three dissolution media. The method was linear in the range of 1.11112–13.3334 µg/mL (r2>0.998). The limits of detection ranged from 0.0157 to 0.0222 µg/mL, and the limits of quantification were between 0.0415 and 0.0546 µg/mL. The recovered values were between 99.4 and 103.0%. No interference from the placebo was observed. The relative standard deviation values were less than 2% for precision. For robustness, different conditions were evaluated as wavelengths, changes in concentration, and Whatman No. 40, 41, and 42 filters; they did not modify the method response. The samples were kept unchanged for a period of 24 hours at 25°C. Conclusions: The UV spectrophotometric method was linear, accurate, specific, and precise in the concentration range studied and in the dissolution media at pH levels of 1.2, 4.5, and 6.8, being suitable for biowaiver studies in pyrazinamide tablets.

Keywords

• antitubercular drugs
• bioequivalence
• drug dissolution
• solubility
• spectrophotometry