Rapid and Sensitive Reverse-phase High-performance Liquid Chromatography Method for Estimation of Ketorolac in Pharmaceuticals Using Weighted Regression

A selective dual quenching sensor (EY/BG@CDs) for simultaneous monitoring of gentamicin and ketorolac levels in plasma: a highly efficient platform that caters to the needs of therapeutic drug monitoring

This research work introduces a novel sensor that utilizes two fluorophores to enable simultaneous monitoring of gentamicin sulphate (GNT) and ketorolac tromethamine (KET). The innovative sensor is composed of carbon dots (CDs) derived from black grapes (BG) and eosin Y (EY) dye. The interaction between the studied drugs and EY/BG@CDs sensor components allows for their simultaneous detection where GNT quenches the fluorescence of EY at 535 nm without affecting the fluorescence of CDs, while KET quenches the fluorescence of BG@CDs at 385 nm without impacting EY fluorescence. The BG@CDs probe was successfully characterized using various techniques such as absorption spectrophotometry, spectrofluorimetry, TEM imaging, infrared spectroscopic analysis, and XRD analysis. The suggested methodology was observed to be highly sensitive for the simultaneous determination of GNT and KET in their spiked rabbit plasma samples, with wide linear ranges and low limit of detection (LOD) values. The studied drugs were extracted using a highly selective extraction method involving protein precipitation followed by mixed mode solid phase extraction using an Oasis WCX cartridge. The simultaneous determination of GNT and KET is essential due to the potential interactions between the studied drugs. Therefore, this analysis can be used to evaluate the necessity of dose monitoring and the potential adverse effects of co-administration of these drugs.

A novel UPLC-MS/MS method for simultaneous quantification of trigonelline, 4-hydroxyisoleucine, and diosgenin from Trigonella foenum-graecum extract: Application to pharmacokinetic study in healthy and type 2 diabetic rats

Trigonelline (TR), 4-hydroxyisoleucine (4-HI), and diosgenin (DG) are the main bioactives of the purified standardized extract of the popular plant Trigonella foenum-graecum L. (TFG), and it has been proven effective for the treatment of various diseases. However, to the best of our knowledge, no study has investigated the pharmacokinetic parameters of purified standardized T. foenum-graecum extract in normal and diabetic Wistar rats. The present study has developed and validated a rapid, reliable, and sensitive simultaneous ultra-performance liquid chromatography MS method to estimate these bioactives. The chromatographic separation was achieved using methanol, acetonitrile, and 0.1% formic acid with the ideal gradient flow system on a BEH Shield RP 18 column. A positive electrospray ionization mode was selected to estimate m/z values of TR (138.14 > 94.63), 4-HI (148.19 > 74.08), and DG (415.54 > 271.33). The method was robust and reproducible over the linearity range of 60-5000, 6-5000, and 15-5000 ng/mL for TR, 4-HI, and DG, respectively. Using this novel validated method, we investigated the pharmacokinetic parameters of bioactives using Phoenix WinNonlin version 8.0 (Certera) in normal and diabetic rats. The assay was successfully applied for the estimation of pharmacokinetic parameters using noncompartmental analysis. This investigation shows that the absorption rate increased, whereas distribution and elimination processes slowed down in diabetic rats compared with normal rats.

Fluorescence-based method for sensitive and rapid estimation of chlorin e6 in stealth liposomes for photodynamic therapy against cancer

Chlorin e6 is a chlorine-based porphyrin containing photosensitizer mainly used for the therapy in cancers like neck and head, early-stage lung cancer, and topical skin cancers. The present study provides a comprehensive account of a highly sensitive, precise, and validated method for the quantification of chlorin e6 in its liposomal formulation. This method is based on the systemic study of the fluorescence action of chlorin e6 in acetonitrile solvent. This experiment follows the analytical method validation parameters as per the International Conference on Harmonization (ICH). Chlorin e6 molecule exhibits strong fluorescence at a wavelength of emission 665 nm, upon excitation at a wavelength of excitation 400 nm in acetonitrile. The linearity of the fluorescence concentration plot was observed over a concentration range of 50 to 1000 ng/mL. The developed and validated method was successfully applied for the estimation of encapsulation efficiency in in-house developed stealth liposomes. Also, stock solution stability and photodegradation study of chlorin e6 were further conducted.

Pre-clinical pharmacokinetic and pharmacodynamic modelling study of 4-hydroxyisoleucine using validated ultra-performance liquid chromatography-tandem mass spectrometry

A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry-based method has been developed for the estimation of 4-hydroxyisoleucine (4-HI), a potent insulinotropic and hypolipidemic agent. The extraction of 4-HI from plasma was accomplished by the protein precipitation technique using l-isoleucine as an internal standard. The separation of analytes was achieved with a mobile phase consisting of acetonitrile and 0.1% formic acid in an isocratic flow system on a BEH Shield RP-18 column (150 mm × 2.1 mm, 1.7 μm). 4-HI and l-isoleucine were detected using an electrospray ionization (ESI) ion source, using multiple reaction monitoring (MRM) in positive ion mode. The precursor to product ion transitions of 4-HI and l-isoleucine were found at m/z values of 148.19 > 74.02 and 132.17 > 69.04, respectively. As per the guidelines for bioanalytical methods, all validation parameter results were within the acceptable range. The method exhibited a robust and reproducible linearity range of 1–5000 ng mL⁻¹ with a coefficient of regression of 0.9999. The method was successfully applied for the estimation of pharmacokinetic parameters after oral administration of 4-HI (10 mg kg⁻¹) in Wistar rats, by using Thoth Pro (version: 4.3) software. Herein, the two-compartment model was statistically fitted based on AIC and SBC values for evaluation of the pharmacokinetic parameters of 4-HI. Pharmacodynamic studies were also performed by measuring the levels of triglyceride and total cholesterol, and showed that the pharmacokinetic and pharmacodynamic data of 4-HI correlated with each other.

A reliable and sensitive UPLC-MS/MS based method has been developed for the estimation of 4-hydroxyisoleucine, a potent insulinotropic and hypolipidemic agent.