Different Spectrophotometric Methods Manipulating Ratio Spectra Applied for the Analysis of Aclidinium in Duaklir® Genuair® Inhalation Powder

Two simple, accurate, and selective spectrophotometric methods were developed to determine aclidinium in the presence of formoterol as interferent compound in Duaklir Genuair inhalation powder. The methods under study are ratio derivative and ratio subtraction spectrophotometric methods. These methods are based on different mathematical processing of the obtained ratio spectra. 'Ihe methods are linear over the concentration range of 5-50 mu/mL for aclidinium and validated according to the ICH guidelines. "Ihe accuracy and precision are found to be within the acceptable limits and assessed by applying the standard addition technique. The specificity of the proposed methods was tested using laboratory-prepared mixtures. Furthermore, the methods were statistically compared to the reported RP-HPLC method, and good results were obtained.