Studies of Food & Drug Interaction with Leflunomide

Leflunomide is a well-known rheumatoid arthritis drug. The study's main objective was to evaluate the food and drug interaction studies of leflunomide/visible spectrophotometer technology. A previously developed selective, observant, and exact UV spectroscopic approach for quantitative analysis of leflunomide was applied here. Stock solutions of 1 mMole (0.027 g dissolved in 100ml volumetric flask in methanol) were prepared and diluted to concentration ranges of 0.01 to 0.055 mMole using the same solvent for the leflunomide assay. 50 g mL<sup>-1</sup> solutions of leflunomide were prepared to study the potential interaction between leflunomide and fruit juices (apple, orange, and grey fruit). Individually, these solutions were diluted in an equimolar ratio and maintained on a water bath at 37±5°C for three hours. The UV/visible spectrophotometer was being used to evaluate these solutions. Although leflunomide and juices remained constant throughout the experiment, the interaction spectra of all juices with the drug showed that the availability of leflunomide was changed in the presence of all juices. In methanol, leflunomide used to have a maximum absorbance in the ultraviolet region at (259nm), but after interaction with fruit juices (apple, orange, and grey fruit), complex formation was indicated by a change in spectrum shape, pattern, and maximum absorbance with an increase in percentage availability (113.90 -139.64%) as the interaction began, λmax shifted to 271 nm. There was a clear interaction between leflunomide and these juices that could change the drug's pharmacological effects. Leflunomide's maximal absorbance in methanol was found to be 259 nm, its spectra changed following interaction with fruit juices, indicating that a complex was formed. Co-administration of these medications should be avoided, as a result.