Fluorescence imaging approaches for the eco-friendly determination of perampanel in human plasma and application for therapeutic drug monitoring

Antiepileptic drugs are among the most common medications for which therapeutic drug monitoring (TDM) is essential. Indeed, TDM provides a realistic approach to adjust drug doses in epilepsy based on plasma concentrations to optimize its clinical outcome. The most common techniques for TDM is HPLC, which has very low green profile among analytical techniques. Perampanel (PER) is an inherently fluorescent compound that its fluorophore readily allows sensitive and quantitative measurements. This paper describes the development and validation of a sensitive, specific and eco-friendly spectrofluorimetric method for the determination of PER. Experimental parameters affecting fluorescence intensity of the compound including diluting solvent, temperature, and excitation wavelength were studied and optimized. The developed spectrofluorimetric method was established in acetonitrile at λ_ex 295 nm and λ_em 431 nm over a concentration range of 5-60 ng/mL. The adopted method was applied for determination of PER in human plasma, it was successful in the range 15-50 ng/mL. The proposed method was found to be sensitive and specific for PER and can be applied successfully in TDM of PER and in QC laboratories.

Application of normal fluorescence and stability-indicating derivative synchronous fluorescence spectroscopy for the determination of gliquidone in presence of its fluorescent alkaline degradation product

Simple, smart and sensitive normal fluorescence and stability-indicating derivative synchronous spectrofluorimetric methods have been developed and validated for the determination of gliquidone in the drug substance and drug product. Normal spectrofluorimetric method of gliquidone was established in methanol at λ excitation 225nm and λ emission 400nm in concentration range 0.2-3μg/ml with LOD equal 0.028. The fluorescence quantum yield of gliquidone was calculated using quinine sulfate as a reference and found to be 0.542. Stability-indicating first and third derivative synchronous fluorescence spectroscopy were successfully utilized to overcome the overlapped spectra in normal fluorescence of gliquidone and its alkaline degradation product. Derivative synchronous methods are based on using the synchronous fluorescence of gliquidone and its degradation product in methanol at Δ λ50nm. Peak amplitude in the first derivative of synchronous fluorescence spectra was measured at 309nm where degradation product showed zero-crossing without interference. The peak amplitudes in the third derivative of synchronous fluorescence spectra, peak to trough were measured at 316,329nm where degradation product showed zero-crossing. The different experimental parameters affecting the normal and synchronous fluorescence intensity of gliquidone were studied and optimized. Moreover, the cited methods have been validated as per ICH guidelines. The peak amplitude-concentration plots of the derivative synchronous fluorescence were linear over the concentration range 0.05-2μg/ml for gliquidone. Limits of detection were 0.020 and 0.022 in first and third derivative synchronous spectra, respectively. The adopted methods were successfully applied to commercial tablets and the results demonstrated that the derivative synchronous fluorescence spectroscopy is a powerful stability-indicating method, suitable for routine use with a short analysis time. Statistical comparison between the results obtained by normal fluorescence and derivative synchronous methods and the official one using student's t-test and F-ratio showed no significant difference regarding accuracy and precision.

Experience with gastrointestinal stapling at the Massachusetts General Hospital

The article describes the reintroduction of the use of stapling devices for intestinal suture at Massachusetts General Hospital in 1976, and reviews the results. Tabulated data of a large number of procedures performed are presented in detail and discussed.