LAUSR

BACKGROUND Low-dose aspirin is prescribed to millions of people around the world as a secondary preventative strategy for the majority of significant cardiovascular events, however it carries a substantial risk of gastric ulcer and bleeding. Cabpirin® tablet, which include low-dose aspirin and vonoprazan fumarate, is approved in Japan for the treatment of acid-related diseases in patients who require low dose of aspirin, but are at risk of aspirin-associated gastric ulcers. OBJECTIVE This paper describes the first published quantitative analytical approaches for the determination of aspirin and vonoprazan fumarate. METHODS The normal UV absorption spectra of aspirin and vonoprazan overlap significantly. The ratio spectra of the studied drugs were created and manipulated by ratio difference and first derivative of ratio spectra approaches. In ratio difference approach, the differences in the amplitude values between 229 and 283 nm enabled the quantitative analysis of aspirin, and the differences in the amplitude values between 255 and 212 nm enabled the quantitative analysis of vonoprazan. In first derivative of ratio spectra approach, the created ratio spectra of each drug were transformed to the first order derivative. aspirin could be determined selectively at 237.40 nm without interference from vonoprazan. Moreover, vonoprazan could be determined selectively at 244 nm without interference from aspirin. RESULTS The applied approaches were validated according to ICH guideline, with good results. Linear correlations were obtained for aspirin and vonoprazan over concentration ranges of 2-25 µg/mL and 1-10 µg/mL, respectively. CONCLUSION The described methods were optimized, validated and applied for determination of the studied drugs in the synthetic mixtures and in pharmaceutical tablets without interferences. HIGHLIGHTS Two spectrophotometric ratio spectra manipulating approaches were developed for the determination of the aspirin and vonoprazan in their pharmaceutical combination tablets.