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Second-Order Derivative UV Spectrophotometric Method for the Determination of Fesoterodine and Comparison with LC, CE and LC-MS/MS in Commercial Extended-Release Tablets.

The present work describes a second-order derivative UV spectrophotometric method for determination of a potent antimuscarinic drug, fesoterodine, in extended-release tablets. The method was developed and satisfactory validated according to ICH guideline with respect to specificity, linearity, precision, accuracy, and robustness. The response was linear in the concentration range of 2-24 µg mL-1 (r2 = 0.9999, n = 7) at wavelength 228 nm, which was the zero crossing point of excipient solutions. The detection and quantitation limits were 0.38 and 1.27 µg mL-1, respectively. Precision and accuracy data evaluated by relative standard deviation were lower than 2%. The method proved to be robust by a Plackett-Burman design evaluation. It is simple, it has low cost, and it has low use of polluting reagents. Therefore, the proposed method was successfully applied for the quantitative analysis of fesoterodine in commercial tablets, and the results were compared to validated methods by liquid chromatography, capillary electrophoresis and liquid chromatography-tandem mass spectrometry showing non-significant difference (P > 0.05).