Simultaneous Determination of D and L Enantiomers of 2-Hydroxyglutarate by UHPLC-MS/MS Method in Human Biological Fluids and its Clinical Application.

2-hydroxyglutarate has limited abundance in normal tissues but a high level under certain pathologic conditions. To clarify the diagnostic value of two chiral isomers of 2-hydroxyglutarate in plasma and urine of Chinese cancer patients, an ultra-high performance liquid chromatography-tandem mass spectrometric method was developed for simultaneous quantification of D-/L-2-hydroxyglutarate. The selected D-/L-2-hydroxyglutarate-d5 as internal standards were added to samples before the SPE on Waters Oasis® MAX 96-Well plate (30 µm, 60 mg). A derivatization step with (+)-O,O'-diacetyl-L-tartaric anhydride permitted the chromatography separation of D-/L-2-hydroxyglutarate on an ACQUITY UPLC-HSS T3 column (50 × 2.1 mm, i.d. 1.8 µm) with acetonitrile and water (containing 0.1% formic acid and 10 mmol ammonium acetate) as the mobile phase. The calibration curves showed good linearity (R ≥ 0.99) over the concentration ranges of 200-5,000 ng/mL and 500-20,000 ng/mL for analysis of D-/L-2-hydroxyglutarate in plasma and urine samples, respectively. Intra- and inter-run precision were ≤ 12.33%, and the accuracy was within the range of -10.44 to 13.90%. This method was further successfully applied to clinical sample analysis in isocitrate dehydrogenase 1/2 mutated Chinese cancer patients.

Population pharmacokinetic model for oral ORIN1001 in Chinese patients with advanced solid tumors.

Background: ORIN1001, a first-in-class oral IRE1-α endoribonuclease inhibitor to block the activation of XBP1, is currently in clinical development for inhibiting tumor growth and enhancing the effect of chemical or targeted therapy. Early establishment of a population pharmacokinetic (PopPK) model could characterize the pharmacokinetics (PK) of ORIN1001 and evaluate the effects of individual-specific factors on PK, which will facilitate the future development of this investigational drug. Methods: Non-linear mixed effect model was constructed by Phoenix NLME software, utilizing the information from Chinese patients with advanced solid tumors in a phase I clinical trial (Register No. NCT05154201). Statistically significant PK covariates were screened out by a stepwise process. The final model, after validating by the goodness-of-fit plots, non-parametric bootstrap, visual predictive check and test of normalized prediction distribution errors, was further applied to simulate and evaluate the impact of covariates on ORIN1001 exposure at steady state up to 900 mg per day as a single agent. Results: A two-compartment model with first-order absorption (with lag-time)/elimination was selected as the best structural model. Total bilirubin (TBIL) and lean body weight (LBW) were considered as the statistically significant covariates on clearance (CL/F) of ORIN1001. They were also confirmed to exert clinically significant effects on ORIN1001 steady-state exposure after model simulation. The necessity of dose adjustments based on these two covariates remains to be validated in a larger population. Conclusion: The first PopPK model of ORIN1001 was successfully constructed, which may provide some important references for future research.

Population pharmacokinetic analysis of TQ-B3203 following intravenous administration of TQ-B3203 liposome injection in Chinese patients with advanced solid tumors.

Background: TQ-B3203 is a novel topoisomerase I inhibitor currently in development for the treatment of advanced solid tumors. Great differences in pharmacokinetic characteristics were found among individuals according to the phase I clinical trial following intravenous administration of TQ-B3203 liposome injection (TLI) in Chinese patients with advanced solid tumors. Thus, it is significant to establish a population pharmacokinetic model to find the key factors and recognize their effect on pharmacokinetic parameters in order to guide individualized administration. Methods: Non-linear mixed effect models were developed using the plasma concentrations obtained from the phase I clinical trial by implementing the Phoenix NLME program. Covariates that may be related to pharmacokinetics were screened using stepwise methods. The final model was validated by goodness-of-fit plots, visual predictive check, non-parametric bootstrap and a test of normalized prediction distribution errors. Results: A three-compartment model with first-order elimination was selected as the best structural model to describe TQ-B3203 disposition adequately. Direct bilirubin (DBIL) and body mass index (BMI) were the two most influential factors on clearance, while lean body weight (LBW) was considered to affect the apparent distribution volume of the central compartment. The population estimations of clearance and central volume were typical at 3.97 L/h and 4.81 L, respectively. Model-based simulations indicated that LBW had a great impact on Cmax, BMI exerted a considerable influence on AUC0-t, and the significance of DBIL on both AUC0-t and Cmax was similarly excellent. Conclusion: The first robust population pharmacokinetic model of TQ-B3203 was successfully generated following intravenous administration of TLI in Chinese patients with advanced solid tumors. BMI, LBW and DBIL were significant covariates that affected the pharmacokinetics of TQ-B3203. This model could provide references for the dose regimen in the future study of TLI.

A validated HPLC-MS/MS method for determination of simmitecan and its metabolite chimmitecan in human plasma and its application to a pharmacokinetic study in Chinese patients with advanced solid tumor.

Simmitecan is a new ester anticancer prodrug which can exert the antiproliferation activity through its active metabolite, chimmitecan. In the current study, a simple and reliable liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination of simmitecan and chimmitecan in human plasma. Both irinotecan and 7-ethyl-10-hydroxycamptothecin were used as the internal standards. Plasma samples were protein precipitated by acetonitrile (0.2% formic acid, v/v) and processed samples were chromatographed on a Hypersil GOLDTM C18 column (100 × 4.6 mm, i.d. 3.0 µm) with acetonitrile and 10 mM ammonium acetate (0.1% formic acid, v/v) as the mobile phase. The calibration curves showed good linearity (R ≥ 0.99) over the concentration range of 1-500 ng/mL and 0.25-125 ng/mL for simmitecan and chimmitecan, respectively. Intra- and inter-run precisions (CV%) were ≤10.2% for simmitecan and ≤12.1% for chimmitecan. The accuracies were 99.4-103.5% for simmitecan and 95.4-103.5% for chimmitecan. This method was further successfully applied to a pharmacokinetic study of simmitecan in Chinese advanced solid cancer patients after administration of simmitecan hydrochloride injection.

Population Pharmacokinetic Modeling and Simulation of TQ-B3101 to Inform Dosing in Pediatric Patients With Solid Tumors.

Background: TQ-B3101 is a novel kinase inhibitor currently in development for the treatment of advanced malignant solid tumor and relapsed or refractory ALK-positive anaplastic large cell lymphoma. Methods: A population pharmacokinetic model was developed using data collected from a Phase 1 study and a Phase 2 study to characterize the pharmacokinetic of TQ-B3101 and its active metabolite (TQ-B3101M). The final model was used to optimize dosing of TQ-B3101 for pediatric patients (6-<18 years) with anaplastic large cell lymphoma. Results: The pharmacokinetic of TQ-B3101 and TQ-B3101M was adequately described by a 1-compartment model with first-order absorption and elimination for parent drug coupled with a 2-compartment model with time-dependent clearance for the metabolite. The clearance of TQ-B3101M decreased over time with a maximum fractional reduction of 0.41. The estimated apparent clearance and apparent volume of distribution of TQ-B3101 were 2850 L/h and 4200 L, respectively. The elimination half-life of TQ-B3101 was 1.0 h. The distribution and elimination half-lives of TQ-B3101M at steady state were 4.9 and 39.4 h, respectively. The projected exposure of TQ-B3101M in virtual pediatric population following the body surface area tiered dosing regimen was similar to that in children pediatric patients after the recommended pediatric dose of crizotinib (280 mg/m2 twice daily), an analog of TQ-B3101M. Conclusion: A population pharmacokinetic model was developed to provide optimal dose of regimen for further development of TQ-B3101 in pediatric patients with anaplastic large cell lymphoma.

A validated UHPLC-MS/MS method for determination of TQ-B3203 in human plasma and its application to a pharmacokinetic study in Chinese patients with advanced solid tumor.

TQ-B3203 is a new topoisomerase I inhibitor derived from camptothecin. In this paper, a simple and reliable ultra high-performance liquid chromatography-tandem mass spectrometric method was developed and validated for determination of TQ-B3203 in human plasma with TQ-B3203-d8 used as the internal standard. Bis(p-nitrophenyl)phosphate (2 mol/L) was added to ensure the stability of TQ-B3203 in human plasma. Plasma samples were protein precipitated by methanol and processed samples were chromatographed on an AQUITY BEH C8 column (50 × 2.1 mm, id 1.7 µm) with acetonitrile and water (0.1% formic acid) as the mobile phase. The calibration curves showed good linearity (R≥0.99) over the concentration range of 0.5-500 ng/mL. Within- and between-run precision were ≤5.8% and the accuracy was within the range of -8.3 to 14.0%. This method was further successfully applied to a pharmacokinetic study of TQ-B3203 in Chinese advanced solid cancer patients after administration of TQ-B3203 liposome injection.

Development and validation of a UHPLC-MS/MS method for the simultaneous determination of five bioactive flavonoids in rat plasma and comparative pharmacokinetic study after oral administration of Xiaochaihu Tang and three compatibilities.

An accurate, rapid, and reliable ultra high performance liquid chromatography with tandem mass spectrometry method was developed and validated for the simultaneous determination of baicalin, wogonoside, baicalein, wogonin, and oroxylin A in rat plasma. Then, the stability of baicalin and baicalein in the preparation of plasma sample was systematically investigated. The Waters BEH C18 column was used with a gradient mobile phase system of acetonitrile and water containing 0.1% formic acid. The analytes were detected in the multiple reaction monitoring mode with positive electrospray ionization. 100 µL fresh plasma was added with 50 µL antioxidant reagent (1 mol/L HCl containing 0.5% Vitamin C), and liquid-liquid extraction with ethyl acetate was used to extract the analytes from plasma. Lower limits of quantification of baicalin, wogonoside, baicalein, wogonin, and oroxylin A were 21.9, 4.80, 1.20, 0.848, and 0.800 ng/mL, respectively. The mean extract recoveries of five flavonoids were 69.1∼89.2%, and the precision and accuracy were within the acceptable limits. This method was further successfully applied to the comparative pharmacokinetic study of these five flavonoids in rats after oral administration of Xiaochaihutang and three compatibilities. The obtained results may be helpful to reveal the mechanism of Xiaochaihutang formula compatibility.

Simultaneous determination of epalrestat and puerarin in rat plasma by UHPLC-MS/MS: Application to their pharmacokinetic interaction study.

In the present study, a simple, rapid and reliable ultrahigh-performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) method was developed and validated to determine simultaneously epalrestat (EPA) and puerarin (PUE) in rat plasma for evaluation of the pharmacokinetic interaction of these two drugs. Both the analytes and glipizide (internal standard, IS) were extracted using a protein precipitation method. The separation was performed on a C18 reversed phase column using acetonitrile and 5 mmol/L ammonium acetate in water as the mobile phase with a gradient elution program. The analytes, including IS, were quantified with multiple reaction monitoring under negative ionization mode. The optimized mass transition ion pairs (m/z) were 318.1 → 274.0 for EPA, 415.1 → 266.9 for PUE and 444.2 → 166.9 for IS. The linear calibration curves for EPA and PUE were obtained in the concentration ranges of 10-4167 and 20-8333 ng/mL, respectively (r > 0.99). The current method was successfully applied for the pharmacokinetic interaction study in rats following administration of EPA and PUE alone or co-administration (EPA 15 mg/kg, oral; PUE 30 mg/kg, intravenous). The results showed that the combination of EPA and PUE could increase t1/2 of EPA and reduce Tmax of EPA. These changes indicated that EPA and PUE might cause drug-drug interactions when co-administrated.

Serum metabonomics study of anti-depressive effect of Xiao-Chai-Hu-Tang on rat model of chronic unpredictable mild stress.

Xiao-Chai-Hu-Tang (XCHT) has been proven to be effective for the clinical treatment of depression. However, the mechanisms of definite antidepressant-like effects and detailed metabolic biomarkers were still unclear in this prior study. Here, we have investigated the metabolic profiles and potential biomarkers in a chronic unpredictable mild stress model after treatment with XCHT. Metabonomics based on ultra-high performance liquid chromatography coupled with mass spectrometry was used to profile the metabolic fingerprints of serum obtained from a rat model with chronic unpredictable mild stress with and without XCHT treatment. The model rats showed a significant decrease in sucrose preference and food consumption, and these depression-like symptoms were significantly improved by XCHT. Through principal component analysis (PCA), nine potential biomarkers of tryptophan, uric acid, phenylalanine, cholic acid and lysophosphatidylcholine (C18:0 LPC, C16:0 LPC, C16:1 LPC, C18:1 LPC, C20:4 LPC) were characterized as potential biomarkers involved the pathogenesis of depression. The therapeutic effect of XCHT on depression may involve in amino acid metabolism, lipid metabolism, oxidative stress and inflammation response. The present investigation highlights that metabonomics is a valuable tool for studying the essence of depression as well as evaluating the efficacy of the corresponding drug treatment.

An intergated serum and urinary metabonomic research based on UPLC-MS and therapeutic effects of Gushudan on prednisolone-induced osteoporosis rats.

Gushudan, a Chinese compound formulation based on the theory of traditional Chinese medicine and desgined to treat osteoporosis. However, its intergated intervention effective mechanism in vivo is not well understood. In this study, an intergated serum and urinary metabonomic strategy based on UPLC-MS technique have been developed to increase the understanding of the metabolism characters of osteoporosis and to investigate the holistic therapeutic efficacy of Gushudan on prednisolone-induced osteoporosis rat model. Principle component analysis (PCA) was utilized to identify differences in metabolic profiles of rats in the control group, prednisolone-induced osteoporosis model group and Gushudan-treatment group and clear separation was achieved among three groups. Furthermore, 17 potential biomarkers from urine and 10 potential biomarkers from serum were identified, primiarily related to amino acid metabolism, energy metabolism, lipid metabolism, intestinal flora metabolism and kidney damage. Gushudan has therapeutic effects on rat with osteoporosis via the regulation of multiple metabolic pathways. It's worth mentioning that some new biomarkers associated with osteoporosis such as 3-methoxydopa, 2,8-digydroxyadenine have been discovered in this study for the first time. This study provides a useful approach to get insight into the intergated metabonomic mechanism of prednisolone-induced osteoporosis and to assess the efficacy of Gushudan on osteoporotic rats. The work also shows that the metabonomics method is a promising tool in the efficacy and mechanism research of traditional Chinese compound medicines.