Analysis of NSAIDs in Rat Plasma Using 3D-Printed Sorbents by LC-MS/MS: An Approach to Pre-Clinical Pharmacokinetic Studies

Analytical sample preparation techniques are essential for assessing chemicals in various biological matrices. The development of extraction techniques is a modern trend in the bioanalytical sciences. We fabricated customized filaments using hot-melt extrusion techniques followed by fused filament fabrication-mediated 3D printing technology to rapidly prototype sorbents that extract non-steroidal anti-inflammatory drugs from rat plasma for determining pharmacokinetic profiles. The filament was prototyped as a 3D-printed sorbent for extracting small molecules using AffinisolTM, polyvinyl alcohol, and triethyl citrate. The optimized extraction procedure and parameters influencing the sorbent extraction were systematically investigated by the validated LC-MS/MS method. Furthermore, a bioanalytical method was successfully implemented after oral administration to determine the pharmacokinetic profiles of indomethacin and acetaminophen in rat plasma. The Cmax was found to be 0.33 ± 0.04 µg/mL and 27.27 ± 9.9 µg/mL for indomethacin and acetaminophen, respectively, at the maximum time (Tmax) (h) of 0.5–1 h. The mean area under the curve (AUC0–t) for indomethacin was 0.93 ± 0.17 µg h/mL, and for acetaminophen was 32.33± 10.8 µg h/mL. Owing to their newly customizable size and shape, 3D-printed sorbents have opened new opportunities for extracting small molecules from biological matrices in preclinical studies.

Progress of Pretreatment and Analytical Methods of Proton Pump Inhibitors: An Update since 2010

Proton pump inhibitors (PPIs) are the most commonly used medication for stomach secretion disorders. However, when it comes to safe, discreet pharmaceutical practice, widely recognized preparational and analytical method(s) for PPIs with sensitivity, selectivity, speed and high accuracy still remains underdeveloped. For this reason, this paper sets out to make a comprehensive review of the preparation and determination methods for PPIs based on multiple matrices since 2010. We have integrated newly-developed techniques (such as solid phase extraction, liquid phase micro-extraction, and solid phase micro-extraction) into conventional sample preparational methods. On the other hand, our analytical techniques include liquid chromatography, supercritical fluid chromatography, capillary electrophoresis, and employment of sensors. In addition, we have identified the pros and cons of each technique and have forecast their future developmental trends.

Pharmacokinetics of Esomeprazole Magnesium After Single Oral Doses in Healthy Subjects: Bioequivalence Study and Food Effects

This study was designed to evaluate the bioequivalence of the newly developed delayed-release oral suspension (test) 40 mg esomeprazole magnesium compared to its marketed counterpart (40 mg; reference) in healthy adult Chinese subjects. We conducted randomized, open-label, two-period, single-dose, two-way crossover trials over a 7-day washout period, comprising a fasting trial and a fed trial. The subjects were administered the test or reference products in a 1:1 ratio at random throughout each period. Then, in the next session, they received the alternate products. Liquid chromatography-tandem mass spectrometry and WinNonlin software were used to assess the bioequivalence of esomeprazole peak plasma concentration (C_max ) and area under the concentration-time curve (AUC). Overall, 33 subjects participated in the fasting trial and 42 subjects participated in the fed trial. Under both situations, the 90% confidence interval for the ratio of geometric means of C_max , AUC_0-t , and AUC_0-∞ were within equivalence ranges (80%-125%). In these trials, no severe adverse events or protocol violations were observed. Moreover, when esomeprazole was administered while fed, the t_max was delayed, and both C_max and AUC were reduced. The results of this research suggest that the test and reference formulations were bioequivalent under fasting and fed states.

Analysis of Different Methods of Extracting NSAIDs in Biological Fluid Samples for LC-MS/MS Assays: Scoping Review

The aim of this study was to carry out a systematic investigation and analysis of different drug extraction methods, specifically non-steroidal anti-inflammatory drugs in biological fluid samples, for Liquid Chromatography in Mass Spectrometry assays (LC-MS/MS). A search was carried out in the main databases between 1999 and 2021, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. Data were obtained through PubMed, Lilacs, Embase, Scopus, and Web of Science databases using the Boolean operators AND and OR. Studies were pre-selected by title and abstract by two independent reviewers. The selected texts were read in full, and only those that were complete and compatible with the inclusion and exclusion criteria were eligible for this research. A total of 248 references were obtained in the databases. After removing the duplicates and analyzing the titles and abstracts, 79 references were evaluated and passed to the next phase, which comprised the complete reading of the article. A total of 39 publications were eligible for this study. In 52% of the studies, the authors used the liquid–liquid extraction method (LLE), while in 41%, the solid-phase extraction method (SPE) was used. A total of 5% used microextraction methods and 2% used less-conventional techniques. The literature on the main methods used, the LLE and SPE methods, is extensive and consolidated; however, we found other studies that reported modifications of these traditional techniques, which were equally validated for use in LC-MS/MS. From this review, it is concluded that the diversity of techniques, reliability, and practical information about each analytical method used in this study can be adapted to advances in LC-MS/MS techniques; however, more ecological, economic, and sustainable approaches should be explored in the future.

Simultaneous determination of naproxen and esomeprazole in beagle dog plasma by supercritical fluid chromatography-tandem mass spectrometry coupled with evaporation-free liquid-liquid extraction

In order to avoid a risk of gastrointestinal toxic caused by naproxen (NAP), esomeprazole (ESOM) is generally used clinically in combination. The present work was undertaken to simultaneously determine NAP and ESOM in beagle dog plasma, and evaluated their pharmacokinetic behaviors in beagle dogs. Herein, ethyl acetate was used to extract the samples by using a time-saving evaporation-free liquid-liquid extraction (EF-LLE) method, then the samples were analyzed by supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS). The optimal analysis conditions were achieved with an ACQUITY UPC2™ BEH column maintained at 50℃ and eluted completely within 2 min using supercritical carbon dioxide and methanol with a gradient elution mode. Due to the large differences in plasma concentrations between NAP and ESOM, celecoxib and diazepam were selected as dual-internal standards (IS). The mass transition ion pairs were m/z 231.2 → 185.0, 346.9 → 198.2, 285.1 → 193.1 and 382.2 → 281.2 for NAP, ESOM, diazepam (IS for NAP) and celecoxib (IS for ESOM), respectively. The concentration of NAP and ESOM were linear within the range of 0.1-100 μg/mL (r > 0.993) and 0.005-5 μg/mL (r > 0.996) in beagle dog plasma, and the accuracy and precision of intra-day and inter-day of all quality control samples were within ±15 %. It was a method with the feature of rapid, sensitive and high-throughput, and would be practical for determining NAP and ESOM in biological samples simultaneously and for assessing their pharmacokinetic behaviors in clinical studies.

Simultaneous separation of naproxen and 6-O-desmethylnaproxen metabolite in saliva samples by liquid chromatography-tandem mass spectrometry: Pharmacokinetic study of naproxen alone and associated with esomeprazole

Naproxen is a widely used non-steroidal anti-inflammatory drug for the control of postoperative inflammatory signs and symptoms in dentistry. Its association with esomeprazole has been widely studied and has yielded good results for the control of acute pain, even with the delayed absorption of naproxen owing to the presence of esomeprazole. To further understand the absorption, distribution, and metabolism of this drug alone and in combination with esomeprazole, we will analyze the pharmacokinetic parameters of naproxen and its major metabolite, 6-O-desmethylnaproxen, in saliva samples. A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometric method for the simultaneous determination of naproxen and 6-O-desmethylnaproxen in saliva will be developed and validated. Sequential saliva samples from six patients will be analyzed before and 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 6 8, 11, 24, 48, 72, and 96 h after the ingestion of one naproxen tablet (500 mg) and esomeprazole-associated naproxen tablets (500 + 20 mg), at two different times. After liquid-liquid extraction with ethyl acetate and HCl, the samples will be analyzed using an 8040 Triple Quadrupole Mass Spectrometer (Shimadzu, Kyoto, Japan). Separation of naproxen and its major metabolic products will be performed using a Shim-Pack XR-ODS 75Lx2.0 column and C18 pre-column (Shimadzu, Kyoto, Japan) at 40°C using a mixture of methanol and 10 mM ammonium acetate (70:30, v/v) with an injection flow of 0.3 mL/min. The total analytical run time will be 5 min. The detection and quantification of naproxen and its metabolite will be validated, which elucidate the pharmacokinetics of this drug, thereby contributing to its proper prescription for the medical and dental interventions that cause acute pain.

Determination of voriconazole and co-administered drugs in plasma of pediatric cancer patients using UPLC-MS/MS: A key step towards personalized therapeutics

Untreated invasive aspergillosis results in high mortality rate in pediatric cancer patients. Voriconazole (VORI), the first line of treatment, requires strict dose monitoring because of its narrow therapeutic index and individual variation in plasma concentration levels. Commonly co-administered drugs; either Esomeprazole (ESO) or Ondansetron (OND) have reported drug-drug interaction with VORI that should adversely alter therapeutic outcomes of the latter. Although VORI, ESO and OND are co-administered to pediatric cancer patients, the combined effect of ESO and OND on the plasma concentration levels of VORI has not been fully explored. In this study, an accurate, reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated for simultaneous determination of VORI, ESO, and OND in ultra-low sample volumes (25 μL) of plasma of pediatric cancer patients. Based on the physicochemical properties of the studied drugs and internal standard, liquid-liquid extraction was successfully adopted with methyl t-butyl ether. Consistent and reproducible recovery of the three drugs and the internal standard were calculated using plasma and matrix matched samples (RE% > 72.97%, RSD < 8.29%). Chromatographic separation was carried out using UPLC with C18 column and a mobile phase of acetonitrile:water:methanol (70:25:5 V/V/V) at 0.3 mL/min. Mass spectrometric determination at positive electrospray ionization in the MRM mode was employed. The analysis was achieved within 4 min over a linear concentration range of 1.00-200.00 ng/mL for the three drugs. The assay validity was assessed as per the Food and Drug Administration guidelines for bioanalytical method validation, and satisfactory results were obtained. The accuracy and precision were within the acceptable limits for the three drugs in both quality control and incurred plasma samples. Matrix effect and process efficiency were investigated in neat solvent, post-extraction matrix, and plasma. Correlation of the plasma concentration levels of the three drugs revealed differences from the reported drug-drug interactions. This confirmed the need for simultaneous determination of VORI and co-administered drugs in order to achieve optimal therapeutic outcomes. To achieve this, analysis results of this study, genetic polymorphisms in CYP2C19 and clinical data will be used to establish one model incorporating all possible factors that might lead to variation in therapeutic outcomes.

Development and validation of a high throughput UPLC-MS/MS method for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma

A high throughput ultra pressure liquid chromatography–mass spectrometry (UPLC–MS/MS) method with good sensitivity and selectivity has been developed and validated for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma using lansoprazole as internal standard (IS). The extraction method based on liquid–liquid extraction technique was used to extract the analytes and IS from of 50 µL of human plasma using methyl tert-butyl ether:ethyl acetate (80:20, v/v), which offers a high recovery. Chromatographic separation of analytes and IS was achieved on a Hypersil gold C₁₈ column using gradient mobile phase consisting of 2 mM ammonium formate/acetonitrile. The flow rate was set at 0.5 mL/min to elute all the analytes and IS within 1.00 min runtime. Detection of target compounds was performed on a triple quadruple mass spectrometer by multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI). Method validation results demonstrated that the developed method has good precision and accuracy over the concentration ranges of 0.1–2000 ng/mL for each analyte. Stability of compounds was established in a battery of stability studies, i.e., bench top, autosampler, dry extract and long-term storage stability as well as freeze-thaw cycles. The validated method has been successfully applied to analyze human plasma samples for application in pharmacokinetic studies.

Identifying the proton transfer reaction mechanism via a proton-bound dimeric intermediate for esomeprazoles by a kinetic method combined with density functional theory calculations

RATIONALE

Esomeprazole analogs are a class of important proton pump inhibitors for the treatment of gastro-esophageal reflux diseases. Understanding the fragmentation reaction mechanism of the protonated esomeprazole analogs will facilitate the characterization of their complex metabolic fate in humans. In this paper, the kinetic method and theoretical calculations were applied to evaluate the fragmentation of protonated esomeprazole analogs.

METHODS

All collision-induced dissociation (CID) mass spectrometry experiments were carried out using electrospray ionization (ESI) ion trap mass spectrometry in positive ion mode. Also the accurate masses of fragments were measured on by ESI quadrupole time-of-flight (QTOF) MS in positive ion mode. Theoretical calculations were carried out by the density functional theory (DFT) method with the 6-31G(d) basis set in the Gaussian 03 program.

RESULTS

In the fragmentation of the protonated esomeprazole analogs, C-S bond breakage is observed, which gives rise to protonated 2-(sulfinylmethylene)pyridines and protonated benzimidazoles. DFT calculations demonstrate that the nitrogen atom of the pyridine part is the thermodynamically most favorable protonation site, and the C-S bond cleavage is triggered by the transfer of this ionizing proton from the nitrogen atom of the pyridine part to the carbon atom of the benzimidazole part to which the sulfinyl is attached. Moreover, with the kinetic plot, the intensity ratios of two protonated product ions yield a linear relationship with the differences in proton affinities of the corresponding neutral molecules, which provides strong experimental evidence that the reaction proceeds via proton-bound 2-(sulfinylmethylene)pyridine/benzimidazole complex intermediates.

CONCLUSIONS

The kinetic method combined with theoretical calculations was successfully applied to probe the proton transfer reaction by proton-bound 2-(sulfinylmethylene)pyridine/benzimidazole complexes in the fragmentation of protonated esomeprazole analogs by ESI CID MS, which is a strong evidence that the kinetic method can be applied in identifying a proton-bound dimeric intermediate in the fragmentation of protonated ions.