Initial Pharmacokinetic Study Research Articles

Simultaneous determination of Pyragrel, a novel anti-thrombotic agent, and its two primary metabolites in plasma by HPLC–MS/MS

Pyragrel is a novel thromboxane A2-synthetase inhibitor for the treatment of cerebral infarction, and it is currently being investigated in phase I clinical trials. This paper reports the first reliable LC–MS/MS method for the simultaneous determination of Pyragrel and its two main metabolites, M1 and M2, in human plasma. All analytes were extracted from human serum using liquid-phase extraction and separated on a Zorbax EcLipse XDB C18 column using isocratic elution with a mobile phase composed of methanol, water and formic acid (65:35:0.1, v/v/v). Determination of the analytes was achieved by tandem-mass spectrometry with positive electrospray ionization. The multiple reaction monitoring transitions under positive electrospray ionization were performed at m/z 329.0 → m/z 135.9 for Pyragrel, m/z 303.1 → m/z 135.0 for M1, m/z 331.2 → m/z 135.0 for M2, and 482.2 → m/z 258.0 for IS, respectively. The following parameters were validated: specificity, recovery, matrix effects, carry-over, linearity, sample stability under a variety of storage and handling conditions, and stock solution stability. The validated method has been successfully applied to an initial pharmacokinetic study in healthy volunteers following intravenous administrations of 60 mg of Pyragrel, and this method will facilitate further studies involving more comprehensive identification of the metabolic profile of Pyragrel and the appropriate dosage regimen.

Development of a robust, sensitive and selective liquid chromatography-tandem mass spectrometry assay for the quantification of the novel macrocyclic peptide kappa opioid receptor antagonist [D-Trp]CJ-15,208 in plasma and application to an initial pharmacokinetic study.

Selective kappa opioid receptor (KOR) antagonists may have therapeutic potential as treatments for substance abuse and mood disorders. Since [D-Trp]CJ-15,208 (cyclo[Phe-d-Pro-Phe-d-Trp]) is a novel potent KOR antagonist in vivo, it is imperative to evaluate its pharmacokinetic properties to assist the development of analogs as potential therapeutic agents, necessitating the development and validation of a quantitative method for determining its plasma levels. A method for quantifying [D-Trp]CJ-15,208 was developed employing high performance liquid chromatography-tandem mass spectrometry in mouse plasma. Sample preparation was accomplished through a simple one-step protein precipitation method with acetonitrile, and [D-Trp]CJ-15,208 analyzed following HPLC separation on a Hypersil BDS C8 column. Multiple reaction monitoring (MRM), based on the transitions m/z 578.1→217.1 and 245.0, was specific for [D-Trp]CJ-15,208, and MRM based on the transition m/z 566.2→232.9 was specific for the internal standard without interference from endogenous substances in blank mouse plasma. The assay was linear over the concentration range 0.5-500ng/mL with a mean r(2)=0.9987. The mean inter-day accuracy and precision for all calibration standards were 93-118% and 8.9%, respectively. The absolute recoveries were 85±6% and 81±9% for [D-Trp]CJ-15,208 and the internal standard, respectively. The analytical method had excellent sensitivity with a lower limit of quantification of 0.5ng/mL using a sample volume of 20μL. The method was successfully applied to an initial pharmacokinetic study of [D-Trp]CJ-15,208 following intravenous administration to mice.

High performance liquid chromatographic determination of YJC-10592, a new chemokine receptor 2 (CCR-2) antagonist, in biological samples

YJC-10592, a new chemokine receptor 2 (CCR-2) antagonist, was newly synthesized for the treatment of asthma and atopic dermatitis. To evaluate the pharmacokinetic characteristics of YJC-10592, a high-performance liquid chromatographic (HPLC) method was developed for the determination of YJC-10592 in rat plasma, urine, and tissue homogenates, using YJC-10450 as an internal standard. The mobile phase was a gradient of acetate buffer (50 mM, pH 3.0) in acetonitrile at a flow rate of 1.0 mL/min. Chromatograms were monitored by an ultraviolet detector at 230 nm. The retention times for YJC-10592 and the internal standard were 8.0 and 6.3 min, respectively, and the lower limits of quantification (LLOQ) for YJC-10592 in rat plasma and urine were 0.05 and 0.2 μg/mL, respectively. The intra- and inter-assay precisions (coefficients of variation, CVs) were generally low (below 11.4 %) for rat plasma and urine samples. The accuracies (relative errors) ranged from 94.2 to 108 %. No interferences from endogenous substances were found. YJC-10592 was stable in rat whole blood but unstable in the liver homogenate. An initial pharmacokinetic study was performed in Sprague–Dawley rats and demonstrated that YJC-10592 has a half-life of 86.8 min and wide tissue distribution. In summary, this HPLC method can be applied to future preclinical and clinical evaluation of YJC-10592.

A quantitative LC-MS/MS method for determination of SP-141, a novel pyrido[b]indole anticancer agent, and its application to a mouse PK study.

In the present study, a specific and sensitive liquid chromatography-triple quadrupole mass spectrometry method was developed and validated for the determination of SP-141, a novel pyrido[b]indole anticancer agent. After a liquid-liquid extraction with n-hexane-dichloromethane-2-propanol (20:10:1, v/v/v) mixture, the analyte was separated on a Kinetex C18 column (50×2.1mm, 2.6μm) with mobile phases comprising of water (0.1% formic acid, v/v) and acetonitrile (0.1% formic acid, v/v) at a flow rate of 0.4mL/min. The test compound (SP-141) and the internal standard (SP-157) were analyzed in the multiple reaction-monitoring mode using the mass transitions m/z 325.1 → 282.0. The method was linear in the concentration range of 0.648-162ng/mL with coefficients of determination (R(2)) of 0.999 in mouse plasma. The lower limit of quantification was 0.648ng/mL. The intra- and inter-day assay precisions (coefficient of variation, %CV) were less than 4.2% and accuracies (relative error, %RE) ranged from -6.1% to 2.1%. The extraction recoveries were between 97.1 and 103.1% and the relative matrix effect was minimal. In addition, SP-141 was found to be stable in the plasma after three freeze-thaw cycles, at 37°C and 4°C for 24h, and at -80°C for 4 weeks. It was also stable in the stock solution at room temperature for 24h and after preparation in the autosampler for 36h. The validated method was successfully applied to an initial pharmacokinetic study of SP-141 in CD-1 mice following intraperitoneal and intravenous administrations.

The new platinum-based anticancer agent LA-12 induces retinol binding protein 4 in vivo

BackgroundThe initial pharmacokinetic study of a new anticancer agent (OC-6-43)-bis(acetato)(1-adamantylamine)amminedichloroplatinum (IV) (LA-12) was complemented by proteomic screening of rat plasma. The objective of the study was to identify new LA-12 target proteins that serve as markers of LA-12 treatment, response and therapy monitoring.MethodsProteomic profiles were measured by surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF MS) in 72 samples of rat plasma randomized according to LA-12 dose and time from administration. Correlation of 92 peak clusters with platinum concentration was evaluated using Spearman correlation analysis.ResultsWe identified Retinol-binding protein 4 (RBP4) whose level correlated with LA-12 level in treated rats. Similar results were observed in randomly selected patients involved in Phase I clinical trials.ConclusionsRBP4 induction is in agreement with known RBP4 regulation by amantadine and cisplatin. Since retinol metabolism is disrupted in many cancers and inversely associates with malignancy, these data identify a potential novel mechanism for the action of LA-12 and other similar anti-cancer drugs.

Preclinical and Clinical Pharmacokinetics of PF-02413873, a Nonsteroidal Progesterone Receptor Antagonist

The recently discovered selective nonsteroidal progesterone receptor (PR) antagonist 4-[3-cyclopropyl-1-(methylsulfonylmethyl)-5-methyl-1H-pyrazol-4-yl]oxy-2,6-dimethylbenzonitrile (PF-02413873) was characterized in metabolism studies in vitro, in preclinical pharmacokinetics in rat and dog, and in an initial pharmacokinetic study in human volunteers. Clearance (CL) of PF-02413873 was found to be high in rat (84 ml · min(-1) · kg(-1)) and low in dog (3.8 ml · min(-1) · kg(-1)), consistent with metabolic stability determined in liver microsomes and hepatocytes in these species. In human, CL was low in relation to hepatic blood flow, consistent with metabolic stability in human in vitro systems, where identified metabolites suggested predominant cytochrome P450 (P450)-catalyzed oxidative metabolism. Prediction of CL using intrinsic CL determined in human liver microsomes (HLM), recombinant human P450 enzymes, and single species scaling (SSS) from pharmacokinetic studies showed that dog SSS and HLM scaling provided the closest estimates of CL of PF-02413873 in human. These CL estimates were combined with a physiologically based pharmacokinetic (PBPK) model to predict pharmacokinetic profiles after oral suspension administration of PF-02413873 in fasted and fed states in human. Predicted plasma concentration versus time profiles were found to be similar to those observed in human over the PF-02413873 dose range 50 to 500 mg and captured the enhanced exposure in fed subjects. This case study of a novel nonsteroidal PR antagonist underlines the utility of PBPK modeling techniques in guiding prediction confidence and design of early clinical trials of novel chemical agents.

Application of liquid chromatography–tandem mass spectrometry method for the simultaneous quantitative analysis of propentofylline and its chiral metabolite M1 in rats

A sensitive and selective liquid chromatographic-electrospray ionization mass spectrometric method for the simultaneous determination of propentofylline and enantiomers of its active metabolite M1 in rat serum, cortex and hippocampus was developed and validated according to GLP procedures. Sample preparations were carried out by liquid-liquid extraction using diethyl ether after the addition of the internal standard (pentoxifylline). The dried residue was reconstituted in mobile phase and injected onto a Chiralpak AD column (10 µm, 250 × 4.6 mm i.d.). The limit of quantification for propentofylline in serum, cortex and hippocampus was set at 0.25 ng/mL and for enantiomers of its metabolite M1 at 1.25 ng/mL. The established LC/ESI-MS/MS method has been successfully applied to an initial pharmacokinetic study of propentofylline and also to assessment of distribution of parent drug and enantiomers of its pharmacologically active metabolite M1 to cortex and hippocampus after intravenous administration of propentofylline to rats at a dose of 5 mg/kg.

Development and validation of an HPLC method for quantitation of BA‐TPQ, a novel iminoquinone anticancer agent, and an initial pharmacokinetic study in mice

We herein describe the development and validation of an HPLC method for the quantitation of 7-(benzylamino)-1,3,4,8-tetrahydropyrrolo [4,3,2-de]quinolin-8(1H)-one (BA-TPQ), a newly synthesized iminoquinone anticancer agent. BA-TPQ was extracted from plasma and tissue samples by first precipitating proteins with acetonitrile followed by a liquid-liquid extraction with ethyl acetate. Chromatographic separation was carried out using a gradient flow rate on a Zorbax SB C(18) column, and the effluent was monitored by UV detection at 346 nm. The method was found to be precise, accurate, and specific, with a linear range of 3.91-1955.0 ng/mL in plasma, 19.55-1955.0 ng/mL in spleen, brain, and liver homogenates and 19.55-3910.0 ng/mL in heart, lung and kidney homogenates. The method was stable under all relevant conditions. Using this method, we also carried out an initial study determining plasma pharmacokinetics and tissue distribution of BA-TPQ in mice following intravenous administration. In summary, this simple and sensitive HPLC method can be used in future preclinical and clinical studies of BA-TPQ.

Development and Validation of a Selective and Robust LC-MS/MS Method, Employing Liquid–Liquid Extraction Based on 96-Well Format Plates, for High-Throughput Quantification of Docetaxel in Small Plasma Samples

To investigate the pharmacokinetic characteristics of a novel nanoliposome-entrapped docetaxel injection, an anti-tumor agent, a high-throughput analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection (LC-MS/MS) was developed for the determination of docetaxel in beagle dog plasma using paclitaxel as the internal standard (I.S.). Most liquid transfer steps, including preparation of calibration standards and quality control samples, as well as the addition of the I.S., were performed by using eight-channel pipetting tools. The analyte and internal standard were isolated from 50 µL plasma samples and chromatographed on a Ultimate XB C-8 column (50 mm × 4.6 mm, 5 µm) with a mobile phase consisting of methanol–water–formic acid (90:10:0.01, v/v/v)pumped at 0.3 mL/min. The method had a chromatographic total run time of 3 min. A Varian 1200 L electrospray tandem mass spectrometer equipped with an electrospray ionization source was operated in selected reaction monitoring (SRM) mode with the precursor-to-product ion transitions m/z 830.0 → 549.0 (docetaxel) and 876.0 → 591.0 (paclitaxel) used for quantitation. The method was sensitive, with a lower limit of quantitation (LLOQ) of 1 ng/mL and good linearity in the range 1–500 ng/mL for docetaxel. All the validation data, such as accuracy, precision, and inter-day repeatability, were within the required limits. The method was successfully applied to initial pharmacokinetic study of nanoliposome-entrapped docetaxel injection in beagle dogs, and the statistical results of the pharmacokinetic data clearly suggest the novel formulation vehicle does control docetaxel's acute side effects to some extent.

An initial pharmacokinetic study with a Metered Dose Transdermal System® for delivery of the progestogen Nestorone® as a possible future contraceptive

Background Transdermal delivery of steroids is gaining popularity for contraception and hormone replacement therapy. This study aimed to test metered spray delivery of a precise dosage of Nestorone® (NES) progestogen as a possible transdermal progestogen-only contraceptive. Study Design Six healthy postmenopausal volunteers, not recently using any hormonal therapies, comprise the sample for this study. Each subject was studied on two occasions with multiple blood sampling for assay of NES over a 24-h period: on the first occasion, after a single dosage of 3×90 μL NES sprays using a specially devised, precisely metered delivery device; on the second occasion, following the fifth in a series of five daily transdermal dosages of 3×90 μL of NES spray. Conventional pharmacokinetic parameters were calculated. NES was assayed in serum using a specific radioimmunoassay. Results Mean serum levels of NES peaked at around 20 h following dosing, and levels plateaued at 285–290 pmol/L after 4–5 days of daily spray application. All subjects achieved satisfactory serum levels, although substantial intersubject variation was noted. The apparent elimination half-life of NES after the last dose on Day 5 was 26.8 h. No unexpected adverse events were encountered. Conclusion This early pharmacokinetic trial of a new transdermal steroid delivery system has demonstrated the feasibility of achieving serum levels of NES sufficient to block ovulation and potentially provide effective contraception.