Quantitative Spectrophotometric Analysis of Celecoxib and Tramadol in Their Multimodal Analgesia Combination Tablets.

Background: Pain is a global, complex health problem that includes physical, emotional, and social components. The pain management process has many goals, including patient satisfaction, reducing clinical complications, and lowering costs. The physician describes pain medications in terms of the proven cause and classification of the severity of the pain. The combination of celecoxib and tramadol was recently approved by the Food and Drug Administration (FDA) in October 2021 for the treatment of acute pain in adults.

Objective: This paper presents the first published quantitative analytical methods for celecoxib and tramadol.

Methods: The UV absorption spectra of celecoxib and tramadol showed strong overlap. Mathematical simultaneous equation and ratio difference methods were developed to resolve the spectral overlap and quantify the drugs in the combination mixture. In the simultaneous equation method, the absorbance and absorptivity values at 252 and 217 nm were used to construct two mathematical equations that were used for the simultaneous mathematical quantification of the above drugs. The mathematical manipulation of the ratio difference based on the calculation of the differences in the amplitude values between 250 and 280 nm enabled the quantitative analysis of celecoxib, and the differences in the amplitude values between 221 and 272 nm enabled the quantitative analysis of tramadol.

Results: The proposed methods were successfully applied to the selective quantitative analysis of celecoxib and tramadol in the synthetic mixtures and in the pharmaceutical tablets without interference from the tablet additives.

Conclusions: The applied methods demonstrated good linearity in the concentration range of 1-20 µg/mL and 3-45 µg/mL for celecoxib and tramadol, respectively, with acceptable accuracy and precision. The methods were found to be sensitive with LOD values of 0.183 µg/mL and 0.626 µg/mL for celecoxib and tramadol, respectively, in simultaneous equation method and of 0.275 µg/mL and 0.772 µg/mL for celecoxib and tramadol, respectively, in ratio difference method.

Highlights: The first established simple and validated UV spectrophotometric methods were described for concurrent quantification of the celecoxib and tramadol in their recently approved pharmaceutical formulation.