Innovative first-order UV and fluorescence spectroscopic methods for the quantification of rufinamide in the presence of its toxic degradant: Application of AGREE tool.

An antiepileptic drug named rufinamide (RUF) is used to treat seizures caused by Lennox Gastaut Syndrome (LGS). Fully sustainable evaluated stability-indicating simple spectrophotometric and spectrofluorometric techniques combined with the first derivative for determining the quantity of rufinamide from RUF-Ninhydrin charge transfer complex by using ninhydrin as an acceptor and its oxidative degradation products, respectively. These methods have been created and thoroughly validated in accordance with ICH requirements. The discipline of pharmaceutical analysis requires diverse stability testing under various conditions. Solubility of RUF in different solvent as well as calorimetric method also performed to check the stability of RUF in different temperature conditions. The rufinamide-ninhydrin complex exhibits absorbance at 594 nm using spectrophotometer and the first derivative appeared at 640 nm. The RUF's fluorescence and the oxidative degradant (OXD) emission appeared at 406 and 426 nm, following the excitation at 373 and 368 nm respectively. By applying Δλ = 20 nm, first-order derivatization of synchronous spectra was able to resolve the overlap and determine rufinamide in the presence of its product of oxidative degradation at 398 nm. Both the developed methods verified linearity ranging from 12.5 to 200 μg mL for spectrophotometer and 0.5-8 μg mL for the spectrofluorimetric method. The limit of quantitation (LOQ) values were of 0.14 and 0.27 μg mL, while the limit of detection (LOD) values were 8.19 and 0.41 μg mL for spectrophotometric and spectrofluorometric methods respectively. AGREE and analytical eco-scale was two of the tools used to assess and approve the proposed method's greenness.