Determination of pitavastatin in human plasma via HPLC-ESI-MS/MS and subsequent application to a clinical study in healthy Chinese volunteers

An Isolated Perfused Rat Liver Model: Simultaneous LC-MS Quantification of Pitavastatin, Coproporphyrin I, and Coproporphyrin III Levels in the Rat Liver and Bile

The isolated perfused rat liver (IPRL) model provides a mechanistic understanding of the organic-anion-transporting polypeptide (OATP/Oatp)-mediated pharmacokinetics in the preclinical evaluation, which often requires the use of control substrates (i.e., pitavastatin) and monitoring endogenous biomarkers (coproporphyrin I and III). This study aimed to develop and validate an LC-MS method allowing the simultaneous quantification of pitavastatin, coproporphyrin I (CPI), and coproporphyrin III (CPIII) in rat liver perfusion matrices (perfusate, liver homogenate, bile). The analysis was performed on a C18 column at 60 °C with 20 μL of sample injection. The mobile phases consisted of water with 0.1% formic acid and acetonitrile with 0.1% formic acid with a gradient flow of 0.5 mL/min. The assay was validated according to the ICH M10 Bioanalytical Method Validation Guideline (2022) for selectivity, calibration curve and range, matrix effect, carryover, accuracy, precision, and reinjection reproducibility. The method allowing the simultaneous quantification of pitavastatin, CPI, and CPIII was selective without having carryover and matrix effects. The linear calibration curves were obtained within various calibration ranges for three analytes in different matrices. Accuracy and precision values fulfilled the required limits. After 60 min perfusion with pitavastatin (1 μM), the cumulative amounts of pitavastatin in the liver and bile were 5.770 ± 1.504 and 0.852 ± 0.430 nmol/g liver, respectively. CPIII was a more dominant marker than CPI in both liver (0.028 ± 0.017 vs 0.013 ± 0.008 nmol/g liver) and bile (0.016 ± 0.011 vs 0.009 ± 0.007 nmol/g liver). The novel and validated bioanalytical method can be applied in further IPRL preparations investigating Oatp-mediated pharmacokinetics and DDIs.

Evaluation of the Pharmacokinetic Drug-Drug Interaction between Micronized Fenofibrate and Pitavastatin in Healthy Volunteers

Dyslipidemia is a major risk factor for development of atherosclerosis and cardiovascular disease (CVD). Effective lipid-lowering therapies has led to CVD risk reduction. This study evaluated the possible pharmacokinetic interactions between fenofibrate, a peroxisome proliferators-activated receptors α agonist, and pitavastatin, a 3-hydoxy-3-methylglutaryl-coenzyme A reductase inhibitor, in healthy Korean subjects. The study design was an open-label, randomized, multiple-dose, three-period, and six-sequence crossover study with a 10-day washout in 24 healthy volunteers. It had three treatments: 160 mg of micronized fenofibrate once daily for 5 days; 2 mg of pitavastatin once daily for 5 days; and 160 mg of micronized fenofibrate with 2 mg of pitavastatin for 5 days. Serial blood samples were collected at scheduled intervals for up to 48 h after the last dose in each period to determine the steady-state pharmacokinetics of both drugs. Plasma concentrations of fenofibric acid and pitavastatin were measured using a validated high-performance liquid chromatography with the tandem mass spectrometry method. A total of 24 subjects completed the study. Pitavastatin, when co-administered with micronized fenofibrate, had no effect on the C_max,ss and AUC_τ,ss of fenofibric acid. The C_max,ss and AUC_τ,ss of pitavastatin were increased by 36% and 12%, respectively, when co-administered with fenofibrate. Combined treatment with pitavastatin and micronized fenofibrate was generally well tolerated without serious adverse events. Our results demonstrated no clinically significant pharmacokinetic interactions between micronized fenofibrate and pitavastatin when 160 mg of micronized fenofibrate and 2 mg of pitavastatin are co-administered. The treatments were well tolerated during the study, with no serious adverse events.

Quantitative bio-analysis of pitavastatin and candesartan in rat plasma by HPLC-UV: Assessment of pharmacokinetic drug-drug interaction

A novel, precise, accurate and rapid HPLC-UV method was developed, optimised and fully validated for simultaneous estimation of pitavastatin (PIT) and candesartan (CAN) in rat plasma using telmisartan as an internal standard. Following liquid-liquid extraction of the analytes from plasma, chromatographic separation was accomplished on a Waters Reliant C18 column (4.6 × 250 mm, 5 µm) using ACN-5 mM Sodium acetate buffer (80:20, v/v; pH adjusted to 3.5 with acetic acid) as mobile phase at a flow rate of 0.8 mL/min and wavelength of 234 nm. The calibration curves were linear over the concentration ranges of 2-400 ng/mL and 3-400 ng/mL for pitavastatin and candesartan respectively. The method when validated as per US-FDA guidelines was found to be precise as well as accurate. Extraction recovery observed for both analytes was above 90% as well as reproducible and consistent. Stability studies showed the samples to be stable over a long period covering from sample collection to final analysis. The method was successfully applied to investigate pharmacokinetic interaction between PIT and CAN in wistar rats. The mean plasma concentration-time curves of PIT and CAN showed that single PIT as well as CAN show similar pharmacokinetic properties to those obtained when co-administrated with each other (P value >0.05). Hence, there is no evidence for a potential drug-drug interaction between PIT and CAN. This information provides evidence for clinical rational use of CAN and PIT in cardiovascular patients.

Electrochemical determination of an anti-hyperlipidimic drug pitavastatin at electrochemical sensor based on electrochemically pre-treated polymer film modified GCE

An electrochemically pretreated silver macroporous (Ag MP) multiwalled carbon nanotube modified glassy carbon electrode (PAN-Ag MP-MWCNT-GCE) was fabricated for the selective determination of an anti-hyperlipidimic drug, pitavastatin (PST). The fabricated electrochemical sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed in quantifying and determining PST through differential pulse adsorptive stripping voltammetry (DPAdSV) and CV. The electrode fabrication proceeded with remarkable sensitivity to the determination of PST. The effect of various optimized parameters such as pH, scan rate (ν), accumulation time (t_acc), accumulation potential (U_acc) and loading volumes of Ag MP-MWCNT suspension were investigated to evaluate the performance of synthesized electrochemical sensor and to propose a simple, accurate, rapid and economical procedure for the quantification of PST in pharmaceutical formulations and biological fluids. A linear response of PST concentration in the range 2.0×10⁻⁷–1.6×10⁻⁶ M with low detection (LOD) and quantification (LOQ) limits of 9.66±0.04 nM and 32.25±0.07 nM, respectively, were obtained under these optimized conditions.

Development of MEPS-UHPLC–MS/MS multistatin methods for clinical analysis

Background: Statins are the microsomal 3-hydroxy-3methylglutaryl-coenzyme A reductase inhibitors used for the treatment of hypercholesterolemia. Some recent studies revealed also the extra-lipid effects and anticancer activities. Due to the wide incidence of cancer diseases, the number of studies dealing with anticancer statin activities has grown in recent years. Development of one universal multistatin method will be a very convenient way of providing practical and economical multiple statin analysis. Results/methodology: Fast and sensitive methods for determination of seven clinically relevant statins, their interconversion products and metabolites (17 analytes in total) in biological samples using microextraction by packed sorbent for sample preparation and UHPLC–MS/MS for subsequent analysis were developed and validated. Three MS platforms with different ion sources, transfer optics, collision cell technologies and scan speed parameters were compared. Conclusion: Significant differences among the methods were observed in terms of selectivity and sensitivity. Microextraction by packed sorbent was successful in the extraction of all 17 analytes from biological matrix.

Rapid and selective determination of pitavastatin calcium in presence of its degradation products and co-formulated drug by first-derivative micelle-enhanced and synchronous fluorimetric methods

New, selective and rapid methods are presented for determination of PIT in the presence of its hydrolytic degradation products and co-formulated drug, EZE. These methods are derivative micelle enhanced native fluorescence and synchronous fluorimetry.

Drug repurposing screen reveals FDA-approved inhibitors of human HMG-CoA reductase and isoprenoid synthesis that block Cryptosporidium parvum growth

Cryptosporidiosis, a diarrheal disease usually caused by Cryptosporidium parvum or Cryptosporidium hominis in humans, can result in fulminant diarrhea and death in AIDS patients and chronic infection and stunting in children. Nitazoxanide, the current standard of care, has limited efficacy in children and is no more effective than placebo in patients with advanced AIDS. Unfortunately, the lack of financial incentives and the technical difficulties associated with working with Cryptosporidium parasites have crippled efforts to develop effective treatments. In order to address these obstacles, we developed and validated (Z' score = 0.21 to 0.47) a cell-based high-throughput assay and screened a library of drug repurposing candidates (the NIH Clinical Collections), with the hopes of identifying safe, FDA-approved drugs to treat cryptosporidiosis. Our screen yielded 21 compounds with confirmed activity against C. parvum growth at concentrations of <10 μM, many of which had well-defined mechanisms of action, making them useful tools to study basic biology in addition to being potential therapeutics. Additional work, including structure-activity relationship studies, identified the human 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitor itavastatin as a potent inhibitor of C. parvum growth (50% inhibitory concentration [IC(50)] = 0.62 μM). Bioinformatic analysis of the Cryptosporidium genomes indicated that the parasites lack all known enzymes required for the synthesis of isoprenoid precursors. Additionally, itavastatin-induced growth inhibition of C. parvum was partially reversed by the addition of exogenous isopentenyl pyrophosphate, suggesting that itavastatin reduces Cryptosporidium growth via on-target inhibition of host HMG-CoA reductase and that the parasite is dependent on the host cell for synthesis of isoprenoid precursors.

Simple LC-MS/MS methods for simultaneous determination of pitavastatin and its lactone metabolite in human plasma and urine involving a procedure for inhibiting the conversion of pitavastatin lactone to pitavastatin in plasma and its application to a pharmacokinetic study

Sometimes, drugs and their metabolites in plasma may convert to each other. This phenomenon is called interconversion, which may result in the instability problem of the plasma samples. The instability problem caused by interconversion of the co-existing metabolites may often be ignored, since there is no drug metabolite in the quality control samples prepared for method validation. Pitavastatin lactone (Pi-LAC), a main metabolite of pitavastatin (Pi), is very unstable and easily converted to Pi in plasma. In this paper, simple and rapid LC-ESI-MS/MS methods were developed for the simultaneous determination of Pi and Pi-LAC in human plasma and urine. The sample stability was examined under different conditions. The interconversion of Pi and Pi-LAC was prevented by adding a pH 4.2 buffer solution to the freshly collected plasma samples. Detection was performed using an electrospray ionization (ESI) operating in positive ion multiple reaction monitoring mode by monitoring the ion transitions from m/z 422.2→290.3 (Pi), 404.2→290.3 (Pi-LAC) and m/z 611.3→423.2 (candesartan cilextetil, the internal standard), respectively. The calibration curve of Pi and Pi-LAC in both human plasma and urine showed good linearity over the concentration range of 0.1-200 ng/mL. The established methods were successfully applied to a pharmacokinetic study of pitavastatin calcium tablets in healthy Chinese volunteers after oral administration of 1, 2 and 4 mg single and multiple doses of pitavastatin calcium. The pharmacokinetic parameters of Pi and Pi-LAC in Chinese volunteers were given respectively. The urinary excretion profiles of Pi and Pi-LAC in Chinese volunteers were also presented. After receiving a single 4 mg oral dose of pitavastatin calcium, the average cumulative urinary excretion percentages of Pi and Pi-LAC in Chinese volunteers were (0.41 ± 0.16)% and (6.1 ± 5.0)%, respectively.

Approach to the patient who is intolerant of statin therapy

Myopathy occurs in approximately 10% of statin-treated patients and is most commonly manifested by myalgias with or without plasma creatine kinase (CK) elevations. Predisposition exists in patients treated with high doses of potent statins and those who are older, female, have a genetic predisposition, and when statins are coadministered with drugs that compete with or inhibit drug metabolism. In symptomatic patients, CK levels may assist in guiding management. If less than five times the upper limit of normal, the existing statin should be titrated to achieve cholesterol goals and the CK repeated when symptoms appear or worsen. In patients with moderate to severe symptoms and any patient with CK elevated to more than 5-fold the upper limit of normal, the statin should be stopped. Once asymptomatic and CK is reduced (if elevated previously), cholesterol goals can be approached by: 1) a different statin (e.g. fluvastatin or pravastatin), starting with a low dose and titrating up; 2) an alternate daily or weekly more potent statin (e.g. rosuvastatin or atorvastatin); or 3) the combination of the lowest tolerated statin with a cholesterol absorption inhibitor (ezetimibe) and/or bile acid sequestrant. Over-the-counter preparations, e.g. red yeast rice, containing natural statin-like agents, or plant sterols can also lower cholesterol. These, however, have limited efficacy to achieve targeted cholesterol levels for most patients. In patients without CK elevations and symptoms, progress can be followed clinically, but in patients who show CK elevations, CK should be monitored. At present, the superiority of one approach has not been demonstrated, and the need for clinical trials in well-characterized patients with statin intolerance cannot be dismissed.

Beneficial direct adipotropic actions of pitavastatin in vitro and their manifestations in obese mice

OBJECTIVE

Prevention of cardiovascular complications in obese patients frequently includes statin administration for coexisting dyslipidemia. Herein, we investigated the impacts of pitavastatin at clinically relevant doses on adipose dysfunction and insulin resistance.

METHODS

We treated 3T3-L1 preadipocytes with 10-100 ng/ml pitavastatin from initiation of differentiation (Day 0) to Day 8 (differentiation/maturation phase) or from Day 8 to Day 16 (post-maturation phase). Subsequently, we administered pitavastatin (6.2mg/day/kg) to 7-week-old female KKAy mice for 6 weeks; untreated KKAy mice served as obese controls.

RESULTS

Pitavastatin impaired neither lipogenesis nor adiponectin expression during the differentiation/maturation phase. During the post-maturation phase, pitavastatin prevented excessive triglyceride accumulation, which was associated with attenuated glucose transporter-4 expression, and dose-dependently upregulated hormone-sensitive lipase expression. Decrements in the adiponectin/plasminogen activator-1 ratio were also dose-dependently inhibited. In KKAy mice, Coulter counter analyses revealed that pitavastatin treatment significantly decreased (by 16.8%) the frequency of hypertrophic adipocytes (>150 microm in diameter) in parametrial adipose pads, of which total weight remained unaltered. Correspondingly, plasma adiponectin was significantly higher in pitavastatin-treated KKAy mice than in the untreated KKAy mice (12.5+/-3.8 microg/ml vs. 8.3+/-1.5 microg/ml, p<0.05). Moreover, the area under the time-glucose curve after intraperitoneal insulin was decreased by 16% in pitavastatin-treated KKAy mice (p<0.05 vs. untreated controls).

CONCLUSIONS

Pitavastatin did not impair differentiation/maturation of preadipocytes and prevented their deterioration with hypertrophy after maturation at clinical concentrations in vitro. These effects likely contributed to improved insulin sensitivity, in an obese model, via prevention of adipocyte hypertrophy and adipocytokine dysregulation.

Solid-phase extraction and liquid chromatography/tandem mass spectrometry assay for the determination of pitavastatin in human plasma and urine for application to Phase I clinical pharmacokinetic studies

A sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and evaluated for the determination of pitavastatin in human plasma and urine. Samples were extracted using solid-phase extraction (SPE). The major benefit of the present method was the high sensitivity, with a lower limit of quantification (LLOQ) of 0.08 ng/mL. Pitavastatin and internal standard (IS, rosuvastatin) were separated on a C(18) column with a mobile phase consisted of methanol/water (75:25, v/v) with 0.05% formic acid. Drug and IS were detected by LC/MS/MS with positive electrospray ionization (ESI). Accuracy and precision for the assay were determined by calculating the intra- and inter-batch variation of quality control (QC) samples at three concentration levels, with relative standard deviations (R.S.D.s) of less than 15%. The developed method was successfully applied to determine pitavastatin in human plasma and urine, and was proved to be suitable for use in Phase I clinical pharmacokinetic study after oral administration of pitavastatin (1, 2 and 4 mg) in healthy Chinese volunteers.