Nano-scale multi-spectroscopic analysis of the anti-fibromyalgia drug pregabalin based on dihydropyridine ring formation with sustainability and whiteness evaluation.

This research addresses the challenge of analyzing pregabalin, a primary amine in a zwitterionic structure, which is difficult to evaluate due to its lack of chromatophore. The study introduces a derivatization assessment using Hantzsch's multicomponent organic reaction to enhance the detectability of pregabalin by forming a highly fluorescent dihydropyridine derivative. This process involves the condensation of pregabalin with acetylacetone and formaldehyde, yielding a yellowish-green compound measurable both colorimetrically at 338 nm and fluorimetrically at an emission wavelength of 486 nm (λ = 408 nm).

Sensitive and selective LC-MS/MS for the determination of tolperisone and etodolac in human plasma and application to a pharmacokinetic study.

Tolperisone and etodolac were proven to have synergistic effect for patients of acute low back pain associated with musculoskeletal spasm. In this work, a specific, highly sensitive and reproducible analytical method was developed and validated for the simultaneous determination of tolperisone and etodolac in human plasma using liquid chromatography-tandem mass spectrometric technique. Liquid-liquid extraction was optimized for sample preparation.