Integration of a facile sustainable resonance Rayleigh scattering switchable-based system for feasible determination of centrophenoxine, a nootropic and antioxidant agent; application to crude materials and dosage forms

The proposed research adheres to a certain methodology to ensure that the technique used for analyzing the centrophenoxine drug is sustainable and green. It is important to highlight that several tools that have been recently developed were utilized as potential indicators of environmental sustainability and applicability. The present research presents a novel and entirely innovative method utilizing ultrasensitive spectrofluorimetry for the detection of centrophenoxine (CPX) drug. The employed methodology in this study involved the utilization of one-step, one-pot, and direct spectrofluorimetric technique, which was found to be both efficient and environmentally sustainable in the validation and assessment of the drug. Simply, when CPX and erythrosine B reagent were combined in an acidic environment, the highly resonance Rayleigh scattering product was immediately produced. The sensitivity limits were observed to be within the range of 15-47 ng mL-1, whereas the linearity was assessed to be in the range of 50-2000 ng mL-1. The optimal settings for all modifiable parameters of the system were ascertained through an analysis of centrophenoxine-erythrosine B complexes. Moreover, the system demonstrated compliance with International Council for Harmonization (ICH) specifications without encountering any issues. The suggested process was then rated on different recent environmental safety measuring metrics to see how good it was for the environment. Fortunately, the WAC standards that combine ecological and functional elements utilizing the Green/Red/Blue (RGB 12) design also acclaimed the current analytical technique as a white one. Additionally, a new applicability evaluation tool (BAGI) was employed to estimate the practicability of the planned method in the analytical chemistry field.

Green Bio-Analytical Study of Gabapentin in Human Plasma Coupled with Pharmacokinetic and Bioequivalence Assessment Using UPLC-MS/MS

Gabapentin (GAB) is a cyclohexane acetic acid, structurally related to the neurotransmitter gamma-aminobutyric acid (GABA), and considered the principal inhibitory neurotransmitter in the central nervous system (CNS) of mammals. An ultra-performance liquid chromatography–tandem mass spectrophotometry (UPLC-MS/MS) method for assessing pregabalin (PRE) in human plasma, was developed and validated, via PRE usage as an internal standard. The plasma underwent protein precipitation using methanol, prior to analysis. Chromatographic separation was completed using a mobile phase of methanol: 0.1% formic acid solution, (65:35, v/v), at a flow rate of 0.2 mL/min, with an isocratic approach, on an Agilent Eclipse plus column (50 × 2.1 mm and 1.8 μm), in 1.6 min of running time. An Agilent triple quadrupole was used for mass analysis, to detect the ion transitions for GAB and PER, respectively, at m/z of 172.1 → 154.1 and 160.10 → 142.10. The calibration curve, over the linear range of 0.050–10.0 μg/mL, showed a high correlation coefficient, r = 0.9993. The limits of detection and quantitation were 13.37 ng/mL and 40.52 ng/mL, respectively, based on the standard deviation and slope equation. The results for intra- and inter-day measurement accuracy and precision were in acceptable ranges. The method was extended into the assessment of oral administrations of GAB at different doses, of one 600 mg/tablet and two capsules (each one of them has 300 mg of GAB), to volunteers who were used in pharmacokinetics and bioequivalent studies. The AGREE assessment tool was used to visualize the proposed method’s greenness degree, which revealed a high AGREE rating score, supporting the accepted method’s greenness profile.

Simultaneous Determination of Tizanidine, Nimesulide, Aceclofenac and Paracetamol in Tablets and Biological Fluids Using Micellar Liquid Chromatography

A simple, sensitive and rapid micellar liquid chromatographic method was developed and validated for simultaneous determination of four drugs, namely, paracetamol (PAR), tizanidine (TZD), aceclofenac (ACF) and nimesulide (NMD). Good chromatographic separation was achieved using Cyano column and micellar mobile phase consisting of 120 mM sodium dodecyl sulfate, 25 mM phosphate buffer and 10% (V/V) butanol. The pH was adjusted to three using phosphoric acid. The total retention time was below 10 min. The analysis was performed at a flow rate of 1 mL/min and a column temperature of 40°C with direct UV detection at 230 nm. Diclofenac sodium was used as the internal standard. The proposed method was validated according to the ICH guidelines and was successfully applied to the analysis of these drugs in their tablet dosage forms with high accuracy. Limits of detection were found to be 0.03, 0.07, 0.033 and 0.11 μg/mL for PAR, ACF, TZD and NMD, respectively. The high sensitivity of developed method permitted its application to the in-vitro determination of the cited drugs in spiked human plasma and urine samples, and the obtained results were satisfactory. However, PAR could not be determined in spiked human urine because its peak overlapped with that of the urine peak.