Dispersive micro solid phase extraction of busulfan from plasma samples using novel mesoporous sorbent prior to determination by HPLC-MS/MS

Green bioanalysis: an innovative and eco-friendly approach for analyzing drugs in biological matrices

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.

Effect of GSTA1 Variants on Busulfan-Based Conditioning Regimen Prior to Allogenic Hematopoietic Stem-Cell Transplantation in Pediatric Asians

Busulfan is widely used as a chemotherapy treatment before hematopoietic stem-cell transplantation (HSCT). However, the response of busulfan is highly variable and unpredictable, whereby the pharmacogenetic interference of glutathione S-transferase (GST) has strong evidence in Caucasians and some adult Asians but not in pediatric Asian patients. This study was aimed at investigating the associations of GST genetic polymorphisms with variations in the pharmacokinetic (PK) properties of busulfan in pediatric Asian patients. This retrospective cohort study recruited 92 pediatric patients. The polymorphism of GSTA1 was genotyped by Sanger sequencing, and GSTM1 and GSTP1 were genotyped by real-time PCR. Drug concentration and PK estimation were identified using an LC-MS/MS method and a noncompartmental model. Statistical analysis was performed by R software. Out of 92 patients, 48 (53%) were males, the mean age was 8.4 ± 5.12 years old, and the average weight was 26.52 ± 14.75 kg. The allele frequencies of GSTA1*B and of GSTM1 and GSTP1* deletions were 16.9%, 68.5%, and 21.2%, respectively. Patients with GSTA1*B had a statistically significant impact on the PK of busulfan, whereas those with GSTM1 and GSTP1 did not (p > 0.05). The carriers of GSTA1*B showed a significant difference compared to noncarriers in terms of t1/2 (for first dose: 161.9 vs. 134.3 min, p = 0.0016; for second dose: 156.1 vs. 129.8, p = 0.012), CL (88.74 vs. 124.23 mL/min, p = 0.0089), Cmax (4232.6 vs. 3675.5 ng/mL, p = 0.0021), and AUC (5310.6 vs. 4177.1 µM/min, p = 0.00033). The augmentation of AUC was around 27.1% in patients carrying the GSTA1*B variant. The GSTA1 polymorphism was significantly associated with variations of the pharmacokinetic properties of busulfan treatment in pediatric Asian patients.

Magnetic dispersive solid phase extraction based on carbonized cellulose-ferromagnetic nanocomposite for screening phthalate esters in aqueous samples

In this work, a sorbent of the carbonized cellulose-ferromagnetic nanocomposite has been proposed for the magnetic dispersive solid phase extraction of some plasticizers in aqueous samples. Carbonized cellulose nanoparticles were prepared by treatment of cellulose filter paper with concentrated sulfuric acid and then loaded on Fe₃O₄ nanoparticles using coprecipitation. This sorbent is compatible with aqueous samples and can be considered as a viable sorbent for extraction of plasticizers from aqueous samples. In this study, magnetic dispersive solid phase extraction is followed by a dispersive liquid-liquid microextraction method. This combination makes the proposed approach as an efficient clean-up method with high enrichment factors for the selected analytes. The enriched analytes are monitored by gas chromatography equipped with a flame ionization detector. Parameters affecting the method efficiency were investigated in details. Under the optimized extraction conditions, limits of detection could reach up to of 0.15-0.50 µg L^-1. The satisfactory enrichment factors of 286-403 were obtained, and the extraction recoveries were found to be in the range of 57-80%. Relative standard deviations were in the range of 3-7% for intra-day and inter-day precisions for six replicate extractions at 25 µg L^-1 of each plasticizer. Calibration curves were linear in wide ranges with coefficients of determination ≥ 0.995. Eventually, efficiency of the prepared sorbent was confirmed by the extraction of some plasticizers from real samples including fruit juices, mineral water, injection solution, cola, and yoghourt drink packed in plastic containers.

LC-MS/MS Method for Rapid Quantification of Progesterone in Rabbit Plasma and Its Application in a Pharmacokinetic Study of the Transdermal Formulation

A rapid and effective method using QuEChERS-based sample preparation procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has been developed and validated to determine progesterone in rabbit plasma. The analyte was extracted from plasma by acetonitrile with phase partitioning by a mixture of magnesium sulfate and sodium chloride. The supernatant was then directly injected into LC-MS/MS in a positive electrospray ionization mode and quantified using progesterone-d9 as the internal standard. The method linearity was in the range from 1 ng/mL (LOQ) to 200 ng/mL. Method recovery was from 86.0% to 103%, and repeatability was lower than 5.5%. The plasma sample was stable for 12 weeks stored at 18 ± 2°C. This method was applied to quantify progesterone in rabbit plasma in a pharmacokinetic study of two transdermal formulations: a reference drug and a eutectic-hydrogel system. The data indicate that the eutectic-hydrogel system's bioavailability was 1.5 times better than that of the reference drug, and the transdermal system is a potential drug delivery system for progesterone.

Dispersive micro-solid phase extraction based on a graphene/polydopamine composite for the detection of pyrethroids in water samples

In this study, a simple, rapid, precise, and environmentally friendly microextraction named dispersive micro-solid phase extraction based on a graphene/polydopamine composite as a sorbent was investigated for the analysis of four pyrethroids (fenpropathrin, cyhalothrin, etofenprox and bifenthrin) in water samples. The graphene/polydopamine composite was successfully synthesized using a one-step method, and was characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. The simplicity and rapidity of dispersive micro-solid phase extraction and the high surface area and adsorptivity of the graphene/polydopamine composite were combined in the proposed method. Several main parameters, including the amount of the sorbent, extraction time, ionic strength and desorption conditions, were independently optimized and the results were compared to find the best extraction setup for dispersive micro-solid phase extraction. Under the optimal conditions, good linearity was observed for all the target analytes, with the coefficient of determination ranging from 0.9997 to 0.9999. The extraction recoveries obtained using the proposed method ranged from 76.81% to 85.29%, and the limits of detection varied from 1.5 to 3 μg L-1. In addition, the relative standard deviation values for the intra-day precision were between 0.41% and 3.00%, while the inter-day precision showed relative standard deviation values ranging from 1.61% to 5.59%. Overall, the figures of merit of the entire procedure showed that this technique could produce satisfactory results in the detection of pyrethroids in water samples or other organic pollutants in the future.