Characterization of Phenolic Profile and Biological Properties of Astragalus membranaceus Fisch. ex Bunge Commercial Samples.

Astragalus membranaceus Fisch. ex Bunge (syn. Astragalus mongholicus Bunge) is one of the notable medicinal and food plants. Therefore, the aim of this study was to calculate the phenolic composition and antioxidant, antimicrobial, as well as enzyme inhibitory [acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYR)] activities with chemometric approaches of the hydromethanolic and water extracts of commercial A. membranaceus samples. Ten individual phenolic compounds were determined using high-performance liquid chromatography (HPLC), and only quercetin was found at a level of above 80 µg/g DW in both extracts. Moreover, the highest antioxidant activity in DPPH, FRAP, ABTS, and CUPRAC assays was found in the sample containing the roots in loose form from USA. A. membranaceus extracts displayed the inhibition zone diameters within the range from 10 to 22 mm antimicrobial activity against S. aureus, while there were no inhibition zones in any extracts in case of E. coli. The extracts of A. membranaceous showed an inhibition rate below 40% against TYR, and among tested extracts, only two samples were able to inhibit BChE with IC50 values of above 30 µg/mL. Correlation analysis showed a highly positive relationship between their phenolic composition and antioxidant activity. Concluding, the obtained results confirmed that A. membranaceus commercial samples could be an important dietary source of natural antioxidants.

DSC, TGA-FTIR and FTIR Assisted by Chemometric Factor Analysis and PXRD in Assessing the Incompatibility of the Antiviral Drug Arbidol Hydrochloride with Pharmaceutical Excipients.

Arbidol hydrochloride is an antiviral product widely used in Russia and China for the treatment of, among other diseases, influenza. In recent years, it has turned out to be highly effective against COVID-19. However, there is little knowledge about its physicochemical properties and its behavior in the presence of various pharmaceutical excipients, which could be useful in the development of new preparations by increasing its solubility and bioavailability. For this reason, binary mixtures composed of arbidol hydrochloride and selected pharmaceutical excipients such as chitosan, polyvinylpyrrolione K-30 and magnesium stearate were prepared and subjected to differential scanning calorimetry (DSC), thermogravimetry combined with Fourier transform infrared spectrometry (TGA-FTIR) and Fourier transform infrared spectrometry (FTIR) analyses. In order to obtain clarity in the interpretation of the outcomes, chemometric calculations with factor analysis (FA) were used. Additionally, a powder X-ray diffraction (PXRD) and an intrinsic dissolution rate study were performed for arbidol hydrochloride itself and in the presence of excipients. As a result of the study, it was revealed that arbidol hydrochloride may undergo polymorphic transformations and be incompatible with chitosan and magnesium stearate. However, mixing arbidol hydrochloride with polyvinylpyrrolidone K-30 guarantees the obtaining of durable and safe pharmaceutical preparations.

SPME as a green sample-preparation technique for the monitoring of phytocannabinoids and endocannabinoids in complex matrices.

The endocannabinoid system (ECS), particularly its signaling pathways and ligands, has garnered considerable interest in recent years. Along with clinical work investigating the ECS' functions, including its role in the development of neurological and inflammatory conditions, much research has focused on developing analytical protocols enabling the precise monitoring of the levels and metabolism of the most potent ECS ligands: exogenous phytocannabinoids (PCs) and endogenous cannabinoids (endocannabinoids, ECs). Solid-phase microextraction (SPME) is an advanced, non-exhaustive sample-preparation technique that facilitates the precise and efficient isolation of trace amounts of analytes, thus making it appealing for the analysis of PCs and ECs in complex matrices of plant and animal/human origin. In this paper, we review recent forensic medicine and toxicological studies wherein SPME has been applied to monitor levels of PCs and ECs in complex matrices, determine their effects on organism physiology, and assess their role in the development of several diseases.

FTIR, Raman spectroscopy and HT-XRD in compatibility study between naproxen and excipients.

Detection of incompatibility between an active pharmaceutical ingredient (API) and excipients, including the selection of the most biopharmaceutical advantageous excipients is extremely important in the pre-formulation process of developing a solid dosage form technology. Therefore, having fast and reliable methods for identifying incompatibility is fundamental in pharmaceutical technology. For this purpose, combined Fourier transform infrared (FTIR) and Raman spectroscopy as well as high-temperature X-ray diffraction (HT-XRD) were used as a new approach for incompatibility detection, whereas differential scanning calorimetry (DSC) was applied as a reference method. In addition, to facilitate the interpretation of FTIR and Raman data, a multivariate analysis was used - hierarchical cluster analysis (HCA). The tests were carried out in mixtures of naproxen (NPX) with eight selected polymer excipients, mixed at a 1:1 ratio. The results of spectroscopic analyses have shown the physical incompatibility of NPX with methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC), sodium starch glycolate (SSG) and sodium carboxymethylcellulose (CMC). HT-XRD studies performed when these mixtures were heated to 156 °C and then cooled to 25 °C showed a decrease in naproxen crystallinity in these mixtures. Furthermore, the results obtained with spectroscopic methods were confirmed by DSC tests and an intrinsic dissolution rate study.

Magnetic Solid-Phase Microextraction Protocol Based on Didodecyldimethylammonium Bromide-Functionalized Nanoparticles for the Quantification of Epirubicin in Biological Matrices.

Due to epirubicin's (EPI) narrow therapeutic index and risk of cardiotoxicity, it is critical to monitor concentrations of this drug when being used to treat cancer patients. In this study, a simple and fast magnetic solid-phase microextraction (MSPME) protocol for the determination of EPI in plasma and urine samples is developed and tested. Experiments were performed using prepared Fe3O4-based nanoparticles coated with silica and a double-chain surfactant-namely, didodecyldimethylammonium bromide (DDAB)-as a magnetic sorbent. All the prepared samples were analyzed via liquid chromatography coupled with fluorescence detection (LC-FL). The validation parameters indicated good linearity in the range of 0.001-1 µg/mL with a correlation coefficient > 0.9996 for plasma samples, and in the range of 0.001-10 µg/mL with a correlation coefficient > 0.9997 for urine samples. The limit of detection (LOD) and limit of quantification (LOQ) for both matrices were estimated at 0.0005 µg/mL and 0.001 µg/mL, respectively. The analyte recovery after sample pretreatment was 80 ± 5% for the plasma samples and 90 ± 3% for the urine samples. The developed method's applicability for monitoring EPI concentrations was evaluated by employing it to analyze real plasma and urine samples collected from a pediatric cancer patient. The obtained results confirmed the proposed MSPME-based method's usefulness, and enabled the determination of the EPI concentration-time profile in the studied patient. The miniaturization of the sampling procedure, along with the significant reduction in pre-treatment steps, make the proposed protocol a promising alternative to routine approaches to monitoring EPI levels in clinical laboratories.

Profiling Docetaxel in Plasma and Urine Samples from a Pediatric Cancer Patient Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with LC-MS/MS.

In recent years, therapeutic drug monitoring (TDM) has been applied in docetaxel (DOC)-based anticancer therapy to precisely control various pharmacokinetic parameters, including the concentration of DOC in biofluids (e.g., plasma or urine), its clearance, and its area under the curve (AUC). The ability to determine these values and to monitor DOC levels in biological samples depends on the availability of precise and accurate analytical methods that both enable fast and sensitive analysis and can be implemented in routine clinical practice. This paper presents a new method for isolating DOC from plasma and urine samples based on the coupling of microextraction and advanced liquid chromatography with tandem mass spectrometry (LC-MS/MS). In the proposed method, biological samples are prepared via ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) using ethanol (EtOH) and chloroform (Chl) as the desorption and extraction solvents, respectively. The proposed protocol was fully validated according to the Food and Drug Administration (FDA) and the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) requirements. The developed method was then applied to monitor the DOC profile in plasma and urine samples collected from a pediatric patient suffering from cardiac angiosarcoma (AS) with metastasis to lungs and mediastinal lymph nodes, who was receiving treatment with DOC at a dose of 30 mg/m2 body surface area. Due to the rarity of this disease, TDM was carried out to determine the exact levels of DOC at particular time points to ascertain which levels were conducive to maximizing the treatment's effectiveness while minimizing the drug's toxicity. To this end, the concentration-time profiles of DOC in the plasma and urine samples were determined, and the levels of DOC at specific time intervals up to 3 days after administration were measured. The results showed that DOC was present at higher concentrations in the plasma than in the urine samples, which is due to the fact that this drug is primarily metabolized in the liver and then eliminated with the bile. The obtained data provided information about the pharmacokinetic profile of DOC in pediatric patients with cardiac AS, which enabled the dose to be adjusted to achieve the optimal therapeutic regimen. The findings of this work demonstrate that the optimized method can be applied for the routine monitoring of DOC levels in plasma and urine samples as a part of pharmacotherapy in oncological patients.

Monitoring of age- and gender-related alterations of endocannabinoid levels in selected brain regions with the use of SPME probes.

INTRODUCTION: The endocannabinoid system consists of different types of receptors, enzymes and endocannabinoids (ECs), which are involved in several physiological processes, but also play important role in the development and progression of central nervous system disorders. OBJECTIVES: The purpose of this study was to apply precise and sensitive methodology for monitoring of four ECs, namely anandamide (AEA), 2-arachidonoyl glycerol (2-AG), N-arachidonoyl dopamine (NADA), 2-arachidonyl glyceryl ether (2-AGe) in selected brain regions of female and male rats at different stages of development (young, adult and old). METHODS: Biocompatible solid-phase microextraction (SPME) probes were introduced into the intact (non-homogenized) brain structures for isolation of four ECs, and the extracts were subjected to LC-MS/MS analysis. Two chemometric approaches, namely hierarchical cluster analysis (HCA) and Principal Component Analysis (PCA) were applied to provide more information about the levels of 2-AG and AEA in different brain structures. RESULTS: 2-AG and AEA were extracted and could be quantified in each brain region; the level of 2-AG was significantly higher in comparison to the level of AEA. Two highly unstable ECs, NADA and 2-AGe, were captured by SPME probes from intact brain samples for the first time. CONCLUSION: SPME probes were able to isolate highly unstable endogenous compounds from intact tissue, and provided new tools for precise analysis of the level and distribution of ECs in different brain regions. Monitoring of ECs in brain samples is important not only in physiological conditions, but also may contribute to better understanding of the functioning of the endocannabinoid system in various disorders.

Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies.

In recent years, off-label use of sirolimus (SIR) has been gaining attention in the clinical practice. However, since it is critical to achieve and maintain therapeutic blood levels of SIR during treatment, the regular monitoring of this drug in individual patients must be implemented, especially in off-label indications of this drug. In this article, a fast, simple, and reliable analytical method for determining SIR levels in whole blood samples is proposed. Sample preparation based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography-mass spectrometry (LC-MS/MS) was fully optimized toward the analysis of SIR and proposed as a fast, simple, and reliable analytical method for determining the pharmacokinetic profile of SIR in whole-blood samples. In addition, the practical applicability of the proposed DLLME-LC-MS/MS method was evaluated by analyzing the pharmacokinetic profile of SIR in whole blood samples obtained from two pediatric patients suffering from lymphatic anomalies, receiving this drug as off-label clinical indication. The proposed methodology can be successfully applied in routine clinical practice for the fast and precise assessment of SIR levels in biological samples, thus allowing SIR dosages to be adjusted in real time during pharmacotherapy. Moreover, the measured SIR levels in the patients indicate the need for monitoring between doses to ensure the optimal pharmacotherapy of patients.

Withania somnifera L.: Phenolic Compounds Composition and Biological Activity of Commercial Samples and Its Aqueous and Hydromethanolic Extracts.

In the present study, the chemical composition and bioactive properties of commercially available Withania somnifera samples were evaluated. The hydromethanolic and aqueous extracts of the tested samples were analyzed in terms of phenolic compound composition, ascorbic acid content, antioxidant and antibacterial activity, and acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Polyphenols and ascorbic acid content, as well as the antioxidant activity, were higher in the aqueous extracts than in the hydromethanolic extracts. Generally, aqueous extracts presented higher antioxidant activity than the hydromethanolic ones, especially in the case of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. Moreover, higher amounts of phenolic acids and flavonoids were found in the hydromethanolic extracts compared to the aqueous ones. Regarding the antibacterial properties, samples 4, 6, and 10 showed the best overall performance with growth-inhibitory activities against all the examined bacteria strains. Finally, the aqueous and hydromethanolic extracts were the most efficient extracts in terms of AChE and BChE inhibitory activities, respectively. In conclusion, our results indicate that W. somnifera possesses important bioactive properties which could be attributed to the high amounts of phenolic compounds. However, a great variability was recorded in commercially available products, suggesting significant differences in the origin of product and the processing method.

SPME as a green sample-preparation technique for the monitoring of phytocannabinoids and endocannabinoids in complex matrices / 药物分析学报

The endocannabinoid system(ECS),particularly its signaling pathways and ligands,has garnered considerable interest in recent years.Along with clinical work investigating the ECS'functions,including its role in the development of neurological and inflammatory conditions,much research has focused on developing analytical protocols enabling the precise monitoring of the levels and metabolism of the most potent ECS ligands:exogenous phytocannabinoids(PCs)and endogenous cannabinoids(endocannabi-noids,ECs).Solid-phase microextraction(SPME)is an advanced,non-exhaustive sample-preparation technique that facilitates the precise and efficient isolation of trace amounts of analytes,thus making it appealing for the analysis of PCs and ECs in complex matrices of plant and animal/human origin.In this paper,we review recent forensic medicine and toxicological studies wherein SPME has been applied to monitor levels of PCs and ECs in complex matrices,determine their effects on organism physiology,and assess their role in the development of several diseases.

Chemical Composition and Antioxidant Properties of Common and Lemon Verbena.

The nutritional profiles of common and lemon verbena leaves were analyzed (proximate constituents, free sugars, organic acids, tocopherols, and fatty acids) and the leaves were prepared in hydromethanolic and aqueous (decoctions and infusions) extracts. The phenolic compound composition and antioxidant activity (2,2-Diphenyl-1-picrylhydrazyl (DPPH); 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric-reducing antioxidant power (FRAP); and cupric-reducing antioxidant capacity (CUPRAC) assays) of the extracts were characterized. The nutritional composition varied between the studied species, with lemon verbena showing higher amounts of protein, ash, and fat than common verbena, whereas the opposite trend was recorded for the dietary fiber content. The main free sugars detected in both species were fructose, glucose, and sucrose, which were present in higher amounts in the common verbena samples. Succinic acid was the most abundant organic acid in both species while high amounts of oxalic acid were detected in lemon verbena. The main fatty acids in both species were α-linolenic, palmitic, and linoleic acid. Regarding the phenolic compound content, the extracts of lemon verbena presented higher amounts of total phenolic compounds (TPCs), total flavonoids (TFs) and total phenolic acids (TPAs) than the common verbena extracts while the aqueous extracts (infusions and decoctions) were richer in TPCs, TFs, and TPAs than the hydromethanolic ones in both species. Nine phenolic compounds were identified and quantified, including seven phenolic acids and two flavonoids. The lemon verbena samples were characterized by higher antioxidant activity compared to the common verbena samples while the aqueous extracts showed higher antioxidant efficacy than the hydromethanolic ones. In conclusion, both species showed promising results in terms of the nutritional value, chemical composition, and antioxidant activities, which were positively correlated with the phenolic compound contents. Moreover, the extraction protocol may affect the chemical composition and bioactive properties of both species, with aqueous extracts showing better results than hydromethanolic ones.

Effects of Fe3O4 Magnetic Nanoparticle Functionalization with Ionic Liquids and a Double-Chained Surfactant on the Pretreatment of Plasma Samples during Drug Extraction.

Ionic liquids (ILs), also known as "designer solvents," comprise a large group of compounds that can improve overall sample preparation performance due to their unique physical and chemical properties. Some of them have a comparable structure to surfactants, which can be also considered as effective extraction solvents. In this study, nine different ILs and a double-chained surfactant were investigated as potential coating materials for iron oxide-based nanoparticles (NPs) used in the pretreatment of human plasma samples. Various methods of synthesizing and functionalizing NPs were employed in fabricating the magnetic sorbents, with the physicochemical properties of the resultant extraction phases (i.e., naked NPs, NPs coated with silica, and NPs coated with silica and selected IL or surfactant) being characterized via X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TG), and transmission electron microscopy (TEM). The effectiveness of the developed NP-based extraction phases was tested by applying them for the extraction of epirubicin hydrochloride (EPI) from plasma samples, followed by analysis via liquid chromatography with fluorescence detection (LC-FL). The results showed that NPs coated with both silica and IL or silica and surfactant provided significantly higher extraction efficiency compared to naked NPs and NPs coated solely with silica. Additionally, the findings also revealed that the adsorption of analytes depends not only on the coating procedure but also on the type of coating material used to functionalize the NPs. Among the tested structures, didodecyldimethylammonium bromide provided the best performance for the functionalization of NP sorbents previously coated with silica.

Raw Meat Contaminated with Cephalosporin-Resistant Enterobacterales as a Potential Source of Human Home Exposure to Multidrug-Resistant Bacteria.

The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European countries, it was 1.2% to 10.1%. Several studies suggest that meat of animal origin could be one of the reservoirs of 3GC-R bacteria. Here, 86 raw meat samples (turkey, pork, chicken and beef) were collected randomly and verified for the presence of 3GC-R bacteria. The 3GC-R bacteria were isolated, identified and characterized phenotypically (antibiotic resistance, motility and biofilm) and genotypically (repetitive-sequence-based rep-PCR) to elucidate any correlations with principal component analysis (PCA). From 28 3GC-R positive samples, 41 strains were isolated, from which the majority belonged to Serratia fonticola (39%), followed by Escherichia coli (19.5%), Enterobacter cloacae (17.1%) and Klebsiella pneumoniae (14.6%). The isolates of E. coli and S. fonticola presented diverse profiles in rep-PCR. Generally, 3GC-R strains were more resistant to antibiotics used in veterinary medicine than in human medicine. PCA derived from antibiotic resistance, motility and biofilm formation of S. fonticola and E. coli strains showed that resistance to beta-lactams was separated from the resistance to other antibiotic classes. Moreover, for the S. fonticola, E. coli and En. cloacae, the type of meat can create a specific tendency towards antibiotic resistance and phenotypic characteristics for S. fonticola, while these relationships were not found for other tested species.

Nanoemulsion supported microemulsion electrokinetic chromatography coupled with selected preconcentration techniques as an approach for analysis of highly hydrophobic compounds.

In this paper, an oil-in-water (O/W) nanoemulsion (NE) prepared by water cold dilution of an O/W microemulsion (ME) was introduced as a sample matrix in microemulsion electrokinetic capillary chromatography (MEEKC) for the highly hydrophobic compounds analysis. Several model compounds with log PO/W values in the 4.1-10.9 range, from different chemical groups, including retinol, α-tocopherol, cholecalciferol, phylloquinone, menaquinone-7, dichlorodiphenyltrichloroethane, ivermectin have been tested. As a proof of the concept of NE formation, a dynamic light scattering technique was employed to determine the size distribution profile of NE particles. Moreover, due to relatively low conductivity of the NE matrix (50-100 times lower in comparison to the separation buffer) and a negative electric charge provided to hydrophobic compounds through NE dispersed phase, NE matrices have been combined with preconcentration techniques based on electrokinetic dosing, namely field amplified sample injection (FASI) and pressure assisted electrokinetic injection (PAEKI). The detection limits for vitamin K1 and K2-MK7 in the NE matrix in combination with FASI (NE-MEEKC-FASI) as well as PAEKI (NE-MEEKC-PAEKI) were up to 42.9 and 12.1 ng mL-1, respectively. In comparison to standard hydrodynamic injection for microemulsion sample matrix NE-MEEKC-PAEKI grant 45-fold improvement in signal sensitivity. The study presents an innovative approach, as it enables the use of preconcentration techniques for highly hydrophobic compounds (log PO/W > 4), which was not previously possible for implementation in the electromigration techniques. Likewise, the use of organic solvents has been reduced by using ME as a solvent for stock solutions and diluting with water prior to the analysis. The application to real samples was investigated using a dietary supplement containing vitamin K2-MK7 obtained from the fermentation product of soybeans.

Simultaneous determination of mitotane, its metabolite, and five steroid hormones in urine samples by capillary electrophoresis using ß-CD2 SDS1 complexes as hydrophobic compounds solubilizers.

Mitotane is a cytotoxic drug used in the treatment of inoperable adrenocortical carcinoma, it inhibits steroidogenesis as well, and therefore monitoring the level of steroid hormones in patients treated with mitotane is a crucial point of therapy. Hence, we have developed a simple, fast, and efficient electrophoretic method combined with reverse polarity sweeping as online preconcentration technique and dispersive liquid-liquid microextraction for the simultaneous determination of mitotane, its main metabolite DDA, and five steroid hormones (progesterone, testosterone, epitestosterone, cortisol, and corticosterone) in urine samples. In addition, a new sample matrix consisting of ß-CD2 SDS1 complexes for a high hydrophobic compounds solubilization was developed. Approach based on the application of ß-cyclodextrin and SDS complex of a ratio 2:1 allowed for hydrodynamic injection into the capillary of a solution containing both mitotane and other analytes. The detection limits of the analytes for the reverse polarity sweeping-dispersive liquid-liquid microextraction method were found to be in the range of 1.5-3 ng/mL, which were approximately 1000 times lower than in the conventional hydrodynamic injection (5 s, 0.5 psi) without any preconcentration procedure. All analytes were completely resolved in less than 13 min by uncoated silica capillary with an inner diameter of 75 µm (ID) × 60 cm. Electrophoretic separation was performed in reverse polarity with a voltage of -25 kV with a background electrolyte (BGE) consisting of 100 mM SDS, 25% ACN, 25 mM phosphate buffer (pH 2.5), and 7 mM ß-cyclodextrin.

The critical evaluation of the effects of imidazolium-based ionic liquids on the separation efficiency of selected biogenic amines and their metabolites during MEKC analysis.

Ionic liquids (ILs) such as imidazole can be used to prevent the sorption of analytes onto the quartz walls of the capillary. Coating the capillary wall with a cation layer increases its surface stability, consequently improving the repeatability of separation process. Currently, examining the effects of dynamic coatings on the capillary wall is an emerging trend in capillary electrophoresis (CE) research. This study uses micellar electrokinetic chromatography (MEKC) to evaluate how ILs in the background electrolyte (BGE) affect the separation efficiency of biogenic amines (BAs). Specifically, this research focuses on 12 ILs built from cations containing an imidazole ring with different alkyl substituents and anions, as well as one IL containing a pyridinium cation with tetrafluoroborate anion. All analyzed ILs, which were added to the BGE in concentrations ranging from 1 to 20 mM, were tested for their ability to improve the electrophoretic separation of selected BAs, namely: homovanillic acid (HVA), vanililmandelic acid (VMA), dihydroxyphenylglicol (DHPG), 3-metoxy-4-hydroxyphenyl glicol (MHPG), normetanephrine (NM), metanephrine (M), and dihydroxyphenylacetic acid (DOPAC). The results showed that the most effective ILs added to the BGE were those with a chloride anion (1-hexyl-3-methylimidazolium chloride [HMIM+Cl-] and 1-ethyl-3-methylimidazolium chloride [EMIM+Cl-]) and those with a tetrafluoroborate anion (1-hexyl-3-methylimidazolium tetrafluoroborate [HMIM + BF4-]). Improved separation efficiency was also obtained for the BGE containing 1-hexyl-3-methylimidazolium hexafluorophosphate [HMIM + PF6-]. On the other hand, ILs with trifluoromethanesulfonate [OTf-] or bis(trifluoromethylsulfonyl)imide [NTf2-] anions, even at low concentrations in the BGE, disturbed the flow of current through the capillary and worsened the separation process. Overall, this study provides a critical evaluation of the impact of different types and concentrations of ILs on the performance of the MEKC method during the analysis of selected BAs.

Control of retention mechanisms on an octadecyl-bonded silica column using ionic liquid-based mobile phase in analysis of cytostatic drugs by liquid chromatography.

This study assesses the potential of using ionic liquids (ILs) as mobile phase additives to control the retention mechanism of four cytostatic drugs: doxorubicin hydrochloride (DOX), epirubicin hydrochloride (EPI), daunorubicin hydrochloride (DAU) and idarubicin hydrochloride (IDA). Chromatographic separations were performed on a C18 analytical column (Discovery C18 150 × 4.6 mm, 5 µm) using six IL anions and four methyl-substituted IL cations with different alkyl chain lengths (alone or with the additional methyl group on the aromatic ring), or with an allyl group added as a cationic substituent. Thus, a total of 17 different ILs were assessed. The aqueous formic acid solution and phosphate buffer were used to compare how mobile phase composition affected the behavior of the analyzed cytostatic agents in the presence of ILs. In addition, the impacts of IL concentration, phosphate buffer concentration, and phosphate buffer pH on the final results were also considered. The ability to change analyte retention without negatively impacting peak shape or analytical efficiency was also controlled via the tailing factor and number of theoretical plates. Based on the results, the tested ILs were classified as either effective or ineffective mobile phase additives for separation of anthracyclines and identification by LC-FL technique.

Assessment of Lipophilicity Descriptors of Selected NSAIDs Obtained at Different TLC Stationary Phases.

Lipophilicity study of selected NSAIDs, the group of the bioactive compounds usually used in humans and animals medicine, with the use of experimental and calculation methods was evaluated. LogP values are proposed and compared as descriptors of the lipophilicity of eleven compounds (from oxicams and coxibs). Obtained data were designated by thin-layer chromatography (TLC) in various chromatographic conditions, with stationary phases with different properties. The mobile phase systems were prepared by mixing the respective amounts of water and organic modifier, methanol and acetone, in the range of 30 to 80% (v/v) in 5% increments. Retention parameters (RF, RM and RM0) were calculated and statistically evaluated to establish correlations. All experimentally determined RM0 values were compared with partition coefficients obtained by computational methods using linear regression analysis. Moreover, in order to extract information about the lipophilicity of compounds from large retention datasets, two chemometric approaches, namely principal component analysis (PCA) and cluster analysis (CA) were carried out. Established models of lipophilicity may have the potential to predict the biological activity of a number of drugs. The presented knowledge may also be of use during drug discovery processes, broadening the knowledge of potential ways to modify the physicochemical properties of chemical compounds.

Sensitive Analysis of Idarubicin in Human Urine and Plasma by Liquid Chromatography with Fluorescence Detection: An Application in Drug Monitoring.

A new approach for the sensitive, robust and rapid determination of idarubicin (IDA) in human plasma and urine samples based on liquid chromatography with fluorescence detection (LC-FL) was developed. Satisfactory chromatographic separation of the analyte after solid-phase extraction (SPE) was performed on a Discovery HS C18 analytical column using a mixture of acetonitrile and 0.1% formic acid in water as the mobile phase in isocratic mode. IDA and daunorubicin hydrochloride used as an internal standard (I.S.) were monitored at the excitation and emission wavelengths of 487 and 547 nm, respectively. The method was validated according to the FDA and ICH guidelines. The linearity was confirmed in the range of 0.1-50 ng/mL and 0.25-200 ng/mL, while the limit of detection (LOD) was 0.05 and 0.125 ng/mL in plasma and urine samples, respectively. The developed LC-FL method was successfully applied for drug determinations in human plasma and urine after oral administration of IDA at a dose of 10 mg to a patient with highly advanced alveolar rhabdomyosarcoma (RMA). Moreover, the potential exposure to IDA present in both fluids for healthcare workers and the caregivers of patients has been evaluated. The present LC-FL method can be a useful tool in pharmacokinetic and clinical investigations, in the monitoring of chemotherapy containing IDA, as well as for sensitive and reliable IDA quantitation in biological fluids.

Extraction and preconcentration of compounds from the l-tyrosine metabolic pathway prior to their micellar electrokinetic chromatography separation.

The prominent biological effects of adrenaline (A), noradrenaline (NA) and dopamine (DA) as well as the clinical importance of their metabolites (such as dihydroxyphenylacetic acid (DOPAC), methoxy­4-hydroxyphenyl glycol (MHPG), dihydroxyphenylglycol (DHPG), metanephrine (M), normetanephrine (NM), vanillylmandelic acid (VMA), homovanillic acid (HVA)) have forced researchers to evaluate new analytical methodologies for their isolation and preconcentration from biological samples. For this reason, the three most popular extraction techniques (dispersive liquid-liquid microextraction (DLLME), solid-phase extraction (SPE), solid-phase microextraction (SPME)) were tested. Micellar electrokinetic chromatography (MEKC) - a mode of capillary electrophoresis - with a diode array detector (DAD) was applied to assess the extraction efficiency. Next, the enrichment factor (EF) of each applied method was calculated in respect to standard mixtures of the analytes at the same concentration levels. The EF results of seven selected metabolites of biogenic amines (BAs) from urine after sample preparation procedures based on twenty-five different protocols (one DLLME, thirteen SPE and eleven SPME) were calculated and compared using hierarchical cluster analysis (HCA). The SPE as well as SPME procedures were proved to be the most effective approaches for the simultaneous extraction of the chosen compounds. Moreover, an ionic liquid (IL) - 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide - added to methanol in SPME additionally could successfully improve the extraction efficiency. It was also confirmed that the HCA approach could be considered a supportive tool in the selection of a suitable sample preparation procedure for that group of endogenous substances.