Development and validation of a sensitive and rapid UHPLC–MS/MS method for the simultaneous quantification of the common active and inactive metabolites of vicagrel and clopidogrel in human plasma

Evaluation on the Metabolic Activity of Two Carboxylesterase Isozymes in Mouse Liver Microsomes by a LC-MS/MS Method

An applicable method for the precise measurement of major carboxylesterase (CESs) activity in liver still limited. Clopidogrel and irinotecan are specific substrates for CES1 and CES2, respectively. Clopidogrel is metabolized to the inactive metabolite clopidogrel carboxylate (CCAM) by CES1. Irinotecan is metabolized to the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38) by CES2. In the present study, the LC-MS/MS method for the determination of CCAM and SN-38 were separately developed to characterize the metabolic activities of CES1 and CES2 in mouse liver microsomal. CCAM was separated on a Ecosil ODS column with an isocratic mobile phase consisted of 5 mmol/L ammonium formate and 0.1% formic acid in water and acetonitrile (15:85, V:V) at a flow rate of 0.4mL/min. SN-38 was separated on a Waters symmetry C18 column with an gradient mobile phase consisted of 5 mmol/L ammonium formate and 0.1% formic acid in water and acetonitrile at a flow rate of 0.3 mL/min. Calibration curves were linear within the concentration range of 100-20,000 ng/mL for CCAM and 1-200 ng/mL for SN-38. The results of method showed excellent accuracy and precision. The recovery rate, matrix effect and stability inspection results were within the acceptance criteria. The optimized incubation conditions were as follows: protein concentration of microsomes were all 0.1 mg/mL, incubation time was 60 min for clopidogrel and 30 min for irinotecan, respectively. This method was sensitive and applicable for the determination of the activity of CESs in the mouse liver microsomes.

Development and validation of a sensitive LC-MS/MS method for simultaneous analysis of clopidogrel and simvastatin and their main metabolites in beagles: Application to pharmacokinetic drug interactions

Clopidogrel (CLP) and simvastatin (SV) are commonly used in combination therapies as anti-cardiovascular drugs. However, the effect of coadministration on the absorption and metabolism of the two drugs in vivo is not clear. This study developed and validated an LC-MS/MS method for the simultaneous determination of CLP, clopidogrel carboxylic acid (CLPCA), 2-oxo-clopidogrel (2-O-CLP), SV, and simvastatin hydroxy acid (SVA) in beagle plasma. Chromatographic separation was achieved on an InfinityLab Poroshell 120 SB-C8 column (2.1 × 100 mm, 2.7 μm) using methanol and 0.1% formic acid in water as the mobile phase at a flow rate of 0.3 mL/min in gradient mode. The lower limits of quantification are 0.1, 0.8, 0.05, 0.05, and 0.05 ng/mL for CLP, CLPCA, 2-O-CLP, SV, and SVA, respectively. The selectivity, linearity, accuracy, precision, extraction recovery, matrix effect, and stability were validated within acceptable criteria. This method was successfully applied to the pharmacokinetic drug interaction study between CLP and SV, and the results revealed that combined administration affected the metabolic rate of CLP, SV, and their metabolites. This study is the first to detect CLP, CLPCA, 2-O-CLP, SV, and SVA simultaneously.

Antiplatelet effect, safety, and pharmacokinetics of vicagrel in patients with coronary artery disease undergoing percutaneous coronary intervention

AIMS

Vicagrel, a novel antiplatelet prodrug to overcome the residual high platelet reactivity of clopidogrel induced by inactive metabolism and cytochrome P450 (CYP) 2C19 polymorphisms, provides favourable antiplatelet inhibition in healthy volunteers. However, its antiplatelet effect and safety in patients with coronary artery disease (CAD) are unclear.

METHODS AND RESULTS

This was a multicentre, randomized, double-blind, triple-dummy, dose-exploring phase II trial comparing the antiplatelet activity and safety of vicagrel at different doses vs. those of clopidogrel in patients with CAD undergoing percutaneous coronary intervention (PCI). The primary endpoint was inhibition of adenosine diphosphate (ADP)-induced platelet aggregation (%IPA) after loading and maintenance doses (LD/MD) at 28 days. Safety endpoints included adverse events (AEs) and Bleeding Academic Research Consortium-defined any bleeding. Pharmacokinetic (PK) profiles and the influence of CYP2C19 polymorphisms were explored in subgroup analysis. Two hundred and seventy-nine patients diagnosed with stable CAD (51.97%), unstable angina (40.86%), and myocardial infarction (7.17%) were randomized to receive vicagrel 20/5 mg (LD/MD), 24/6 mg, or 30/7.5 mg or clopidogrel 300/75 mg in combination with aspirin. %IPAs on Day 28 were 30.19%, 35.02%, 45.61%, and 32.55% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, respectively, and were comparable across all groups (P = 0.0694). The plasma concentration of the vicagrel active metabolite M15-2 had a similar area under curve and Tmax to those of clopidogrel. There were no significant differences in AEs (4.35%, 0%, 1.45%, and 5.56% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, P = 0.6667) or any bleeding (13.04%, 14.06%, 11.59%, and 11.11% for vicagrel 20/5, 24/6, and 30/7.5 mg and clopidogrel, respectively, P = 0.95) across four groups. %IPAs and PK profiles of vicagrel did not vary significantly among different CYP2C19 metabolizers.

CONCLUSION

Vicagrel had comparable antiplatelet effect and safety to clopidogrel in patients with CAD undergoing PCI.

A molecularly imprinted polymerized high internal phase emulsion adsorbent for sensitive chemiluminescence determination of clopidogrel

A molecularly imprinted polymerized high internal phase emulsion (MIP-polyHIPE) adsorbent was used for selective separating and preconcentrating the anti-plaque drug, clopidogrel. For the first time in this study, chemiluminescence (CL) methods were evaluated for the determination of clopidogrel. The synthesis of adsorbents by the emulsion templating method showed that the sensitivity of the method can be increased up to 42 times. The determination of clopidogrel was evaluated by Ru(phen)₃²⁺-Cerium (IV), KMnO₄-H₂SO₄, KMnO₄-H₂SO₄-Na₂SO₃, and luminol-H₂O₂ CL systems. According to the results, only the Ru(phen)₃²⁺-Cerium (IV) CL system showed a reasonable sensitivity for clopidogrel. Using MIP-polyHIPE adsorbent, the linear range, the limit of detection, and relative standard deviation for clopidogrel in this system were respectively 1.0 × 10^-9-8.0 × 10^-8 mol L^-1, 3.0 × 10^-10 mol L^-1, and 6.3% (n = 4, 1.0 × 10^-8). The proposed method was employed for determining clopidogrel in pharmaceuticals and blood serum samples. The results showed the good sensitivity and accuracy of the proposed method.

Pharmacokinetics, mass balance, and metabolism of [14C]vicagrel, a novel irreversible P2Y12 inhibitor in humans

Vicagrel, a novel irreversible P2Y₁₂ receptor inhibitor, is undergoing phase III trials for the treatment of acute coronary syndromes in China. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of vicagrel in six healthy male Chinese subjects after a single oral dose of 20 mg [¹⁴C]vicagrel (120 µCi). Vicagrel absorption was fast (T_max = 0.625 h), and the mean t_1/2 of vicagrel-related components was ~38.0 h in both plasma and blood. The blood-to-plasma radioactivity AUC_inf ratio was 0.55, suggesting preferential distribution of drug-related material in plasma. At 168 h after oral administration, the mean cumulative excreted radioactivity was 96.71% of the dose, including 68.03% in urine and 28.67% in feces. A total of 22 metabolites were identified, and the parent vicagrel was not detected in plasma, urine, or feces. The most important metabolic spot of vicagrel was on the thiophene ring. In plasma pretreated with the derivatization reagent, M9-2, which is a methylated metabolite after thiophene ring opening, was the predominant drug-related component, accounting for 39.43% of the radioactivity in pooled AUC_0-8 h plasma. M4, a mono-oxidation metabolite upon ring-opening, was the most abundant metabolite in urine, accounting for 16.25% of the dose, followed by M3-1, accounting for 12.59% of the dose. By comparison, M21 was the major metabolite in feces, accounting for 6.81% of the dose. Overall, renal elimination plays a crucial role in vicagrel disposition, and the thiophene ring is the predominant metabolic site.

Development and validation of a LC-MS/MS method for the enantioseparation and determination of clopidogrel bisulfate in beagle plasma and its application to a stereoselective pharmacokinetic study

A rapid and sensitive chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the enantioseparation and determination of clopidogrel bisulfate enantiomers in beagle plasma was established and successfully applied to a stereoselective pharmacokinetic study. The chromatographic separation was achieved on an Ultron ES-OVM column (150 × 2.0 mm, 5 μm) with acetonitrile-ammonium acetate (10 mM, pH 4.5) (22:78, v/v) at a flow rate of 0.3 mL/min. The mass detection was conducted using multiple reaction monitoring mode with the transition of the m/z 322.00→212.00 for clopidogrel and m/z 285.00→193.00 for diazepam (IS), respectively. The calibration curve was linear at the range of 1-800 ng/mL (r²>0.997) for each enantiomer. The intra- and inter-day precision (CV%) was within 10.9 % and the accuracy was at the range of 88.5 %-101.3 % for both enantiomers. The extraction recovery was >90.2 % and no obvious matrix effect was observed. The pharmacokinetic results showed that the R-CB have higher Cmax and AUC than that of S-CB. It is first time to find the chiral inversion between S-CB and R-CB in beagle.

Impacts of CYP2C19 genetic polymorphisms on bioavailability and effect on platelet adhesion of vicagrel, a novel thienopyridine P2Y12 inhibitor

AIMS

We investigated the impacts of CYP2C19 polymorphisms on pharmacokinetics and pharmacodynamics of vicagrel in healthy Chinese subjects.

METHODS

CYP2C19 extensive metabolizers (EMs), intermediate metabolizers (IMs) and poor metabolizers (PMs; 16 subjects/group) participated in a randomized, open-label, 2-period cross-over study. Each study period lasted 7 days, with a loading dose of 24 mg of vicagrel or 300 mg of clopidogrel on day 1, and maintenance doses of 6 mg of vicagrel or 75 mg of clopidogrel daily from day 2 to day 7. The pharmacokinetics and pharmacodynamics were assessed on day 1 and day 7.

RESULTS

After a loading dose, the AUC_0-t of the active metabolite H4 by vicagrel was slightly lower in IMs and PMs (decreased by 21 and 27%, respectively) compared to EMs. Similar results were found after maintenance doses. In EMs, the AUC_0-t of H4 by vicagrel was somewhat higher than clopidogrel after the loading dose, and comparable with clopidogrel (90% confidence interval 0.94, 1.21) after the maintenance doses. However, it was much higher than clopidogrel in PMs, with a 1.28-fold (loading dose) and a 73% (maintenance doses) increases compared to clopidogrel (P < 0.001). Consequently, the inhibition of platelet aggregation by vicagrel was greater than clopidogrel after both loading dose (28.2 vs 12.4% at 4 hours, P < 0.01) and maintenance doses (42.8 vs 24.6% at 4 hours, P < 0.001) in PMs.

CONCLUSIONS

CYP2C19 polymorphisms have less impact on vicagrel as compared to clopidogrel. Drug exposure and response to vicagrel in PMs were even higher than to clopidogrel in IMs.

Development and validation of a UPLC-MS/MS method for simultaneous determination of vicagrel and its major metabolites in rat or human plasma: An optimized novel strategy for the stabilization of vicagrel

Vicagrel is a promising novel antiplatelet drug. However, the quantification of vicagrel in plasma is currently unavailable since it is liable to be hydrolyzed in plasma by esterases. In this study, an optimized strategy was developed and validated to stabilize vicagrel, 2-oxo-clopidogrel (thiolactone metabolite), and H4 (active thiol metabolite) before quantification of the analytes, such as addition of citric acid (for plasma acidification) and NaF (a non-specific esterase inhibitor) to inhibit esterase activity, immediate addition of a thiol-alkylating reagent MPB into blood samples to derivatize H4 for the formation of stable H4 derivative (i.e., MP-H4), use of the anticoagulant K₂EDTA to minimize the conversion of 2-oxo-clopidogrel to H-endo, and keeping the analytes at 4 °C or on wet ice to minimize degradation of the analytes when processed and analyzed. The stability was measured as percent of each analyte remained in plasma samples after their storage for 4 h at 4 °C or in blood samples after 1 h at 4 °C. The results indicated that stability of vicagrel was increased significantly in stabilized plasma or blood samples compared with non-stabilized controls for rats and humans, respectively, and that the stability of 2-oxo-clopidogrel was increased to a certain extent. In contrast, MP-H4 formed was stable in plasma immediately after thorough mixture of MPB with blood. We conclude that the above strategy is useful for improving the stability of vicagrel, 2-oxo-clopidogrel, and H4 in rat or human plasma, and that vicagrel and its two major metabolites can be quantified accurately and simultaneously.

Clopidogrel as a donor probe and thioenol derivatives as flexible promoieties for enabling H2S biomedicine

Hydrogen sulfide has emerged as a critical endogenous signaling transmitter and a potentially versatile therapeutic agent. The key challenges in this field include the lack of approved hydrogen sulfide-releasing probes for in human exploration and the lack of controllable hydrogen sulfide promoieties that can be flexibly installed for therapeutics development. Here we report the identification of the widely used antithrombotic drug clopidogrel as a clinical hydrogen sulfide donor. Clopidogrel is metabolized in patients to form a circulating metabolite that contains a thioenol substructure, which is found to undergo spontaneous degradation to release hydrogen sulfide. Model studies demonstrate that thioenol derivatives are a class of controllable promoieties that can be conveniently installed on a minimal structure of ketone with an α-hydrogen. These results can provide chemical tools for advancing hydrogen sulfide biomedical research as well as developing hydrogen sulfide-releasing drugs.

Hydrogen sulphide (H₂S) is a gaseous signalling molecule, which has shown therapeutic value. Here, the authors show that a thioenol metabolite of the antithrombotic drug clopidogrel is an efficient H₂S donor and masked thioenols can be linked to existing compounds to develop H₂S-releasing agents.

Evaluation of Tolerability, Pharmacokinetics and Pharmacodynamics of Vicagrel, a Novel P2Y12 Antagonist, in Healthy Chinese Volunteers

Background: Vicagrel is a novel anti-platelet drug and hydrolyzed to the same intermediate as clopidogrel via esterase, instead of CYP2C19. Here we report the first clinical trial on the tolerability, pharmacokinetics and pharmacodynamics of different doses of vicagrel, and comparison with clopidogrel in healthy Chinese volunteers. Methods: This study was conducted in two parts. Study I was a dose-escalating (5-15 mg) study. For each dose, 15 participants were randomized into three groups (total n = 45); nine participants were given vicagrel, three were given clopidogrel, and three were given a placebo. Study II was conducted to assess interactions between vicagrel and aspirin in 15 healthy participants. The plasma concentrations of the metabolites of vicagrel and clopidogrel were determined using a LC-MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y12 assay. Results: Vicagrel (5-15 mg per day) dosing for 10 days or addition of aspirin was well tolerated in healthy volunteers. The exposure of the active metabolite increased proportionally across the dose range and was higher (~10-fold) than clopidogrel. The levels of IPA dosing 75 mg clopidogrel were between the responses of 5 mg and 10 mg vicagrel. After a single loading dose of vicagrel (30 mg) and a once-daily maintenance dose (7.5 mg) for 8 days, the maximum inhibition of platelet aggregation was similar to that seen with the combined use of vicagrel and aspirin (100 mg/day). Conclusion: Oral vicagrel demonstrated a favorable safety profile and excellent anti-platelet activity, which could be a promising P2Y12 antagonist as anti-platelet drug and can be further developed in phase II/III studies, and marketing for the unmet medical needs of cardiovascular diseases. The study was registered at http://www.chictr.org.cn (ChiCTR-IIR-16009260).