SPE-UHPLC-ESI-MS/MS Analysis of Cocaine and Its Metabolites in Conventional and Alternative Biological Specimens: Application to Real Samples.

An increase in cocaine abuse has been observed globally since the past decade. Cocaine is among the commonly abused stimulants used for recreational purposes. In this study, the SPE-UHPLC-MS/MS method was developed and validated to be applied on real specimens of 20 chronic cocaine abusers to quantify cocaine/metabolites in conventional as well as alternative biological matrices. Cocaine was extracted from biological specimens using solid-phase extraction followed by liquid chromatography tandem mass spectrometry analysis. Chromatographic separation was achieved on a Poroshell120EC-18 column (2.1 mm × 50 mm, 2.7 µm particle size) using water-acetonitrile in 0.1% formic acid as a mobile phase in gradient elution mode. The flow rate of the mobile phase was 0.5 mL/min with a gradient varying the percentage of acetonitrile linearity ranging 15-95% in 6.0 min acquisition time, and the injection volume was set at 5 µL. Positive electrospray ionization with multireaction ion monitoring mode using two ion transitions for cocaine/metabolites and one for cocaine-d3 was employed. The quantification method demonstrated good linear ranges of 0.025-250 ng/mL in blood, urine, and oral fluid (ng/mg for hair and nail) with a ≥0.991% determination coefficient. The detection limit and lower quantification limit were 0.005 and 0.025 ng/mL in all matrices, respectively. The mean extraction recovery and ionization suppression ranged from 89.3 to 99.8% and -4.6 to -14.4% in the studied matrices. Within-run and between-days precisions were 1.8-7.2% and 1.9-6.1%, respectively. This study will not only help in quantifying cocaine/metabolites in alternative specimens (hair, nail, and oral fluid) but also guide clinical and forensic toxicologists in interpretation of exhumation cases. Furthermore, multiple specimens' analyses can be of significance in estimating the time/manner of drug exposure, in confirming the results of laboratories in cases of doubtful clinical histories, or in aiding medico-legal investigations.

Enhancing therapeutic efficacy: sustained delivery of 5-fluorouracil (5-FU) via thiolated chitosan nanoparticles targeting CD44 in triple-negative breast cancer.

Our current study reports the successful synthesis of thiolated chitosan-based nanoparticles for targeted drug delivery of 5-Fluorouracil. This process was achieved through the ionic gelation technique, aiming to improve the efficacy of the chemotherapeutic moiety by modifying the surface of the nanoparticles (NPs) with a ligand. We coated these NPs with hyaluronic acid (HA) to actively target the CD44 receptor, which is frequently overexpressed in various solid malignancies, including breast cancer. XRD, FTIR, SEM, and TEM were used for the physicochemical analysis of the NPs. These 5-Fluorouracil (5-FU) loaded NPs were evaluated on MDA-MB-231 (a triple-negative breast cell line) and MCF-10A (normal epithelial breast cells) to determine their in vitro efficacy. The developed 5-FU-loaded NPs exhibited a particle size within a favorable range (< 300 nm). The positive zeta potential of these nanoparticles facilitated their uptake by negatively charged cancer cells. Moreover, they demonstrated robust stability and achieved high encapsulation efficiency. These nanoparticles exhibited significant cytotoxicity compared to the crude drug (p < 0.05) and displayed a promising release pattern consistent with the basic diffusion model. These traits improve the pharmacokinetic profile, efficacy, and ability to precisely target these nanoparticles, offering a potentially successful anticancer treatment for breast cancer. However, additional in vivo assessments of these formulations are obligatory to confirm these findings.

HPLC method development and validation for in vitro and in vivo quantification of vancomycin in rabbit plasma.

Vancomycin (VAN) is an effective antibiotic due to its broad-spectrum bactericidal action. High performance liquid chromatography (HPLC), a powerful analytical technique is used for the in vitro/ in vivo quantification of VAN. The current study was aimed to detect the VAN from in vitro as well as the plasma after the extraction from blood of rabbits. The method was developed and validated according to International Council on Harmonization (ICH) Q2 R1 guidelines. Results showed that the peak of VAN was recorded at 2.96 and 2.57 min, respectively in vitro and serum. The coefficient of VAN turned out to be >0.9994 each for in vitro and in vivo samples. VAN was found linear in the range of 6.2-25000ng/mL. The values of accuracy and precision in terms of coefficient of variation (CV) were less than 2%, indicating the validity of the method. The values for LOD and LOQ were estimated to be 1.5 and 4.5ng/mL, correspondingly, which were lower than the values calculated from in vitro media. Furthermore, the score of the greenness found out to be 0.81, depicting good score using AGREE tool. It was concluded that the developed method was found accurate, precise, robust, rugged, linear, detectable and quantifiable at prepared analytical concentrations and could be used for in vitro and in vivo VAN determination.