Electromembrane extraction of anthracyclines from plasma: Comparison with conventional extraction techniques

UHPLC-MS/MS Assay for Quantification of Legubicin, a Novel Doxorubicin-Based Legumain-Activated Prodrug, and Its Application to Pharmacokinetic and Tissue Distribution Studies

Legubicin, a novel prodrug based on doxorubicin, has both albumin-binding and legumain-activating properties. The aim of this study was to develop and validate a UHPLC-MS/MS method for investigating the in vivo pharmacokinetics and tissue distribution profiles of legubicin in rats and tumor-bearing mice following intravenous administration, and to compare this prodrug with the positive control drug doxorubicin. The study employed a UHLC-MS/MS method to determine the levels of albumin-bound of legubicin and two metabolites (free Leu-DOX and DOX) in plasma, tumor, and tissue samples. This method was validated for good selectivity, high sensitivity, excellent extraction recovery, and short run time. The results showed that legubicin was present in the circulation in vivo mainly in a protein-bound form with larger AUC values and lower clearance and distribution, and essentially released small amounts of doxorubicin. Compared to administration of equimolar doses of doxorubicin, legubicin showed increased exposure of the active drug in the tumor and decreased the level of the active drug in the heart and kidney. This study provides valuable information on the pharmacokinetics and tissue distribution of legubicin, implicating its potential as a novel and effective drug candidate for anti-cancer therapies.

Magneto-Fluorescent Mesoporous Nanocarriers for the Dual-Delivery of Ofloxacin and Doxorubicin to Tackle Opportunistic Bacterial Infections in Colorectal Cancer

Cancer-related opportunistic bacterial infections are one major barrier for successful clinical therapies, often correlated to the production of genotoxic factors and higher cancer incidence. Although dual anticancer and antimicrobial therapies are a growing therapeutic fashion, they still fall short when it comes to specific delivery and local action in in vivo systems. Nanoparticles are seen as potential therapeutic vectors, be it by means of their intrinsic antibacterial properties and effective delivery capacity, or by means of their repeatedly reported modulation and maneuverability. Herein we report on the production of a biocompatible, antimicrobial magneto-fluorescent nanosystem (NANO3) for the delivery of a dual doxorubicin-ofloxacin formulation against cancer-related bacterial infections. The drug delivery capacity, rendered by its mesoporous silica matrix, is confirmed by the high loading capacity and stimuli-driven release of both drugs, with preference for tumor-like acidic media. The pH-dependent emission of its surface fluorescent SiQDs, provides an insight into NANO3 surface behavior and pore availability, with the SiQDs working as pore gates. Hyperthermia induces heat generation to febrile temperatures, doubling drug release. NANO3-loaded systems demonstrate significant antimicrobial activity, specifically after the application of hyperthermia conditions. NANO3 structure and antimicrobial properties confirm their potential use in a future dual anticancer and antimicrobial therapeutical vector, due to their drug loading capacity and their surface availability for further modification with bioactive, targeting species.

Electromembrane extraction of clenbuterol from swine urine for monitoring illegal use in livestock

The illegal use of clenbuterol seriously endangers food safety and human health. Accurate monitoring the illegal use of clenbuterol in livestock can efficiently prevent the clenbuterol residue pork products from entering the consumer market. Thus, in this study, a simple, rapid and sensitive method for the determination of clenbuterol in swine urine was developed using electromembrane extraction combined with liquid chromatography-tandem mass spectrometry. It should be noted that the electromembrane extraction method presented many advantages of simple operation, fast mass transfer rate, good sample clean-up capability and less organic solvent consumption. The effect of important factors on the extraction efficiency of clenbuterol was investigated. Under the optimal conditions, good linearity was achieved for clenbuterol over the range of 1-1000 ng/mL (R² = 0.9996). The recoveries of clenbuterol in swine urine at three spiked levels ranged from 83.7 to 110.0% with relative standard deviation values lower than 9.7% (n = 4). Limits of detection and quantification for clenbuterol were 0.07 and 0.25 ng/mL, respectively. These results suggested that the proposed method has great potential on the extraction and determination of trace analyte in complex sample matrix for monitoring the illegal use in livestock. This article is protected by copyright. All rights reserved.

Advanced microextraction techniques for the analysis of amphetamines in human breast milk and their comparison with conventional methods

Breast milk analysis provides useful information about acute newborn exposure to harmful substances, such as psychoactive drugs abused by a nursing mother. Since breast milk represents a complex matrix with large amounts of interfering compounds, a comprehensive sample pre-treatment is necessary. This work focuses on determination of amphetamines and synthetic cathinones in human breast milk by microextraction techniques (liquid-phase microextraction and electromembrane extraction), and their comparison to more conventional treatment methods (protein precipitation, liquid-liquid extraction, and salting-out assisted liquid-liquid extraction). The aim of this work was to optimize and validate all the extraction procedures and thoroughly assess their advantages and disadvantages with special regard to their routine clinical use. The applicability of the extractions was further verified by the analysis of six real samples collected from breastfeeding mothers suspected of amphetamine abuse. The membrane microextraction techniques turned out to be the most advantageous as they required low amounts of organic solvents but still provided efficient sample clean-up, excellent quantification limit (0.5 ng mL^-1), and good recovery (81-91% and 40-89% for electromembrane extraction and liquid-phase microextraction, respectively). The traditional liquid-liquid extraction as well as the salting-out assisted liquid-liquid extraction showed comparable recoveries (41-85% and 63-88%, respectively), but higher quantification limits (2.5 ng mL^-1 and 5 ng mL^-1, respectively). Moreover, these methods required multiple operating steps and were time consuming. Protein precipitation was fast and simple, but it demonstrated poor sample clean-up, low recovery (56-58%) and high quantification limit (5 ng mL^-1). Based on the overall results, microextraction methods can be considered promising candidates, even for routine laboratory use.

Electrocolorimetric gel-based sensing approach for simultaneous extraction, preconcentration, and detection of iodide and chromium (VI) ions

A total integrated electrocolorimetric sensing approach consisting of gel-based electromembrane extraction and colorimetric detection in a one-step process was developed. This system was designed using colorimetric reagents preadded to the agarose gel for the determination of the following two model analytes: iodide and hexavalent chromium [Cr(VI)]. In this system, when a voltage was applied, the analytes were extracted and transferred from the sample solution (donor phase) to the gel (acceptor phase). The analytes then simultaneously reacted with the colorimetric reagents inside the gel, yielding blue and violet colors for iodide and Cr(VI), respectively. These colors were then analyzed using a portable spectrometer and could also be distinguished with the naked eye. Parameters affecting the extraction efficiency were studied and optimized for both analytes. The gel composition for iodide detection was 4% (w/v) agarose, 5% (v/v) H₂O₂, and 1% (w/v) starch in 2 mM HCl. The gel composition for Cr(VI) detection was 2% (w/v) agarose and 1% (w/v) DPC in 0.5 mM HNO₃. Both analytes were extracted at an applied potential of 50 V, an extraction time of 15 min and a stirring rate of 600 rpm. Under the optimized conditions, the developed systems provided linear responses within 15 min for iodide concentrations ranging from 50 to 250 μg L^-1 with a detection limit of 18 μg L^-1 and for Cr(VI) concentrations ranging from 30 to 125 μg L^-1 with a detection limit of 5 μg L^-1. Finally, these systems were successfully applied to the determination of iodide in iodide food supplement samples and Cr(VI) in drinking water samples, showing a negligible matrix effect. This integration could also be extended to other analytes and detection systems to develop sensitive, on-site, and environmentally friendly sensing approaches.

The electromembrane extraction of pharmaceutical compounds from animal tissues

The reliable analysis of various compounds from tissue requires a tedious sample preparation. The sample pretreatment usually involves proper homogenization that facilitates extraction of target analytes, followed by an appropriate sample clean-up preventing matrix effects. Electromembrane extraction (EME) seems to have a significant potential to streamline the whole procedure. In this study, the applicability of EME for direct isolation of analytes from animal tissues was investigated for the first time. Extraction conditions were systematically optimized to isolate model analytes (daunorubicin and its metabolite daunorubicinol) from various tissues (myocardium, skeletal muscle and liver) coming from a pharmacokinetic study in rabbits. The relative recoveries of daunorubicin and its metabolite in all tissues, determined by the UHPLC-MS/MS method, were higher than 66 and 75%, respectively. Considerably low matrix effects (0 ± 8% with CV lower than 6%) and negligible content of phospholipids detected in EME extracts demonstrate the exceptional effectiveness of this microextraction approach in purification of tissue samples. The difference in the concentrations of the analytes determined after EME and reference liquid-liquid extraction of real tissue samples was lower than 12%, which further emphasized the trustworthiness of EME. Moreover, the considerable time reduction needed for sample treatment in case of EME must be emphasized. This study proved that EME is a simple, effective and reliable microextraction technique capable of direct extraction of the analytes from pulverized tissues without the need for an additional homogenization or purification step.

Selective extraction and determination of steroidal glycoalkaloids in potato tissues by electromembrane extraction combined with LC-MS/MS

For the first time, electromembrane extraction (EME) combined LC-MS/MS was applied to extract and determine α-solanine and α-chaconine in different potato tissues using NPOE containing 20% (v/v) DEHP as supported liquid membrane (SLM). Under the optimal conditions, the proposed EME-LC-MS/MS method was evaluated using spiked fresh potato peel sample. The linear range for α-solanine and α-chaconine was 5-1000 ng mL^-1 (R² > 0.9991), with LOD and LOQ of 1.2-1.5 ng mL^-1 and 4.1-5.2 ng mL^-1, respectively. Repeatability for α-solanine and α-chaconine at three concentration levels was satisfactory (<4.9%), and recoveries ranged from 73% to 106%. Finally, the EME-LC-MS/MS method has been successfully employed to determine α-solanine and α-chaconine in sprouted potato peel and tuber samples, indicating that EME exhibited high selectivity and efficient sample clean-up capability. Consequently, EME showed great potential for extraction and purification of toxic and bioactive basic compounds from complex plant tissues.