Application of Different UV Spectrophotometric Methods for Quantitative Analysis of Acotiamide and Esomeprazole.

Background: Acotiamide and esomeprazole are co-administrated and prescribed for gastrointestinal disorder diseases.
Objective: Development of the first UV spectrophotometric methods for the quantitative analysis of acotiamide and esomeprazole in their mixture.
Methods: The UV absorption spectra of acotiamide and esomeprazole showed severe overlapping. To solve the spectral overlapping and quantify the studied drugs in their mixture, simultaneous equation and ratio difference methods were developed. For simultaneous equation method, the absorbance and absorptivity values at 279 and 302 nm were used to construct two mathematical equations applied for the spectrophotometric assay of the cited drugs. Ratio difference spectra manipulated method was developed and enabled successful quantitative determination of acotiamide and esomeprazole. The differences in the amplitude values between 280 and 260 nm enabled estimation of acotiamide, and the differences in the amplitude values between 303 and 282 nm enabled estimation of esomeprazole.
Results: The proposed methods succeeded to quantify acotiamide and esomeprazole in the synthetic mixtures and in their pharmaceutical tablets without any interference from each other or from tablet additives.
Conclusions: The applied methods demonstrated good linearity in the concentration range of 2-30 µg/mL and 2-20 µg/mL for acotiamide and esomeprazole, respectively, with acceptable accuracy and precision. The methods were found to be sensitive with LOD values of 0.336 µg/mL and 0.332 µg/mL for acotiamide and esomeprazole, respectively, in simultaneous equation method and of 0.410 µg/mL and 0.333 µg/mL for acotiamide and esomeprazole, respectively, in ratio difference method.
Highlights: Simple and validated UV spectrophotometric methods were described for selective quantification of the acotiamide and esomeprazole in their mixture.
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