Comprehensive investigation of pharmacodyamic material basis of Wikstroemia indica (L.) C. A. Mey. by serum pharmacochemistry and bivariate correlation analysis.

In this study, the theory of serum pharmacochemistry of traditional Chinese medicine was used to analyze the constituents absorbed into serum after oral administration of Wikstroemia indica (L.) C. A. Mey. by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The micro-liquid dilution method was used to determine the minimum inhibitory concentration of the serum containing Wikstroemia indica. The bivariate correlation analysis method was used to study the spectral-efficiency relationship between the drug-containing serum and the antibacterial activity, and find the main antibacterial active components in serum containing Wikstroemia indica. A total of 26 serum migration components were identified or speculated in the samples, including 11 prototype components and 15 metabolites. Of which, syringic acid, caffeic acid, dihydrocaffeic acid, 4-hydroxybenzoic acid, hippuric acid, 3-hydroxy-3-(4-hydroxy-3-methoxyphenyl)propanoic acid, triumbelletin, (7R)-3-hydroxy-1-methyl-2-oxo-7-(prop-1-en-2-yl)-2,3,5,6,7,8- hexahydroazulene-4- carbaldehyde and (1S,3aS,8aS)-1,3,5-trihydroxy-1,4-dimethyl-7-(propan-2- ylidene) octahydroazulen-6(1H)-one were bacteriostatic active substances. It is the first time to study the constituents in serum containing Wikstroemia indica and reveal its antibacterial pharmacodyamic material basis. The above works provide scientific reference for the in-depth study of Wikstroemia indica.

Interference of eltrombopag with bilirubin measurements on the Vitros 5600 analyzer.

BACKGROUND: Eltrombopag is a thrombopoietin-receptor agonist used to restore platelet count to hemostatic levels in chronic immune thrombocytopenia. The drug has shown to have hepatobiliary adverse effects, but also positive interference with the analytical measurement of bilirubin. Understanding the degree of interference of this drug with bilirubin testing becomes relevant in the clinical management of these patients. METHODS: Eltrombopag at concentrations ranging from 10 to 150 µg/ml was spiked into plasma samples with different baseline concentrations of bilirubin. Total bilirubin, conjugated, and unconjugated bilirubin were measured for each sample using VITROS TBILI and BuBc slides on the Vitros 5600 automated chemistry platform, and interference was assessed. RESULTS: Plasma samples spiked with eltrombopag yielded falsely elevated bilirubin measurements compared to baseline, with the degree of elevation increasing with greater concentrations of eltrombopag. Bilirubin values were increased relative to baseline across all groups, except in conjugated bilirubin measurements in samples with low baseline conjugated bilirubin. For samples with low total bilirubin at baseline, >100 µg/ml of eltrombopag resulted in an error of >+0.6 mg/dl on the measured total bilirubin. For samples with low unconjugated bilirubin at baseline, the error for the same concentrations was >+0.7 mg/dl. CONCLUSION: Our results show that, at supra-physiologically high concentrations, eltrombopag can positively interfere with bilirubin measurements on Vitros 5600 platform.

Metabolite reanalysis revealed potential biomarkers for COVID-19: a potential link with immune response.

Aim: To understand the pathological progress of COVID-19 and to explore the potential biomarkers. Background: The COVID-19 pandemic is ongoing. There is metabolomics research about COVID-19 indicating the rich information of metabolomics is worthy of further data mining. Methods: We applied bioinformatics technology to reanalyze the published metabolomics data of COVID-19. Results: Benzoate, ß-alanine and 4-chlorobenzoic acid were first reported to be used as potential biomarkers to distinguish COVID-19 patients from healthy individuals; taurochenodeoxycholic acid 3-sulfate, glucuronate and N,N,N-trimethyl-alanylproline betaine TMAP are the top classifiers in the receiver operating characteristic curve of COVID-severe and COVID-nonsevere patients. Conclusion: These unique metabolites suggest an underlying immunoregulatory treatment strategy for COVID-19.

Pharmacokinetics and metabolism of LNP023 in rats by liquid chromatography combined with electrospray ionization-tandem mass spectrometry.

In this study, a simple and sensitive LC-tandem mass spectrometric method was developed and validated for the determination of LNP023 in rat plasma. The plasma sample was precipitated with acetonitrile and then separated on an ACQUITY HSS T3 column (50 mm × 2.1 mm, 1.8 µm) using 0.1% formic acid in water and acetonitrile as the mobile phase. The MS detection was performed in positive multiple-reaction monitoring mode with precursor-to-product ion transitions of m/z 423.3 → 174.1 and m/z 435.3 → 367.1 for LNP023 and olaparib (internal standard), respectively. The developed assay was validated in the linear range of 0.1-1000 ng/mL with correlation coefficient (r) greater than 0.9992. The validation parameters were all within the acceptable limits. The validated method has been successfully used to investigate the pharmacokinetics of LNP023 in rat plasma, and our results indicated that LNP023 showed low clearance and high bioavailability (62.2%). Furthermore, four minor metabolites from rat plasma were detected and identified by LC combined with high-resolution mass spectrometry. The metabolic pathways were O-deethylation (M1), hydroxylation (M4), oxidation (M3), and acyl-glucuronidation (M2).

A simple HPLC assay for determining eltrombopag concentration in human serum.

Eltrombopag, a thrombopoietin receptor agonist, is used for the treatment of idiopathic thrombocytopenic purpura (ITP) and aplastic anemia. We developed a HPLC assay for the determination of serum eltrombopag concentration in ITP patients. An aliquot of a serum sample spiked with diclofenac as the internal standard (IS) was treated with acetonitrile to precipitate the proteins. Eltrombopag and the IS were separated on an octadecylsilyl silica-gel column using a mobile phase consisting of 10 mM 1-pentanesulfonic acid sodium salt, acetonitrile, and acetic acid. The detection wavelength was set at 265 nm. The calibration curve was linear at the concentration range of 0.15-12.5 µg/mL for eltrombopag (r = 0.9987). The recoveries of eltrombopag from the serum samples were greater than 95.9% with coefficients of variation (CVs) being less than 2.8%. The CVs for the intra-day and inter-day assays were 1.9-11.8% and 1.0-11.8%, respectively. This assay method could be used for therapeutic drug monitoring of eltrombopag in ITP patients.

Nine absorbed components pharmacokinetic of raw and processed Moutan Cortex in normal and blood-heat and hemorrhage syndrome model rats.

Raw Moutan Cortex (RMC) and Processed Moutan Cortex (PMC) have a long history of use in China and other Asian countries. In this study, a rapid and accurate ultra-high-pressure liquid chromatography coupled with diode array detector (UHPLC-DAD) method was developed and validated for the simultaneous determination of nine absorbed compounds of RMC/PMC. After extraction by protein precipitation with methanol from plasma, the analytes were separated on an Acquity UPLC® BEH Shield RP18 column (2.1 × 100 mm, 1.7 µm, Waters, USA). Acetonitrile (A) and 0.1% (v/v) formic acid in water (B) were selected as the mobile phase to perform gradient elution. The linearity of nine analytes was >0.9915. The intra- and inter-assay precision (RSD) values were within 11.18%, and accuracy ranged from 91.32 to 101.29%. Suitable stability, matrix effect and extraction recoveries were also obtained. The validated method was applied to compare the pharmacokinetics of RMC and PMC in Blood-Heat and Hemorrhage Syndrome Model and normal rats. The results revealed that processing and the pathological state could influence the pharmacokinetic characteristics of compounds in RMC/PMC. The study willbe useful for further studies on pharmacokinetics and clinical application of raw and processed Moutan Cortex.

Comprehensive characterization and resolution of discrepant spectrophotometric bilirubin results in patients on eltrombopag therapy.

Background Eltrombopag is a thrombopoietin receptor agonist used for the treatment of thrombocytopenic conditions. It can cause pH-dependent discoloration of plasma/serum. Eltrombopag is potentially hepatotoxic. It can affect the assessment of hyperbilirubinemia because of its (i) absorbance at ~450 nm (bilirubin), (ii) absorbance at ~550 nm (diazo-bilirubin) and (iii) it can cause yellowish discoloration of the eyes at normal circulating bilirubin levels. Methods We collected 66 samples from patients on a range of eltrombopag dosages up to 150 mg daily. Bilirubin was measured using multiple routine spectrophotometric analyzers, the Doumas reference method and high-performance liquid chromatography (HPLC). Plasma/serum eltrombopag concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spike-in and admixture experiments delineated the effects of eltrombopag and its metabolites. Results Forty-nine of 52 samples from patients on ≥50 mg daily eltrombopag therapy showed significantly discrepant inter-analyzer total bilirubin results, a difference up to 64 µmol/L (3.7 mg/dL). In one sample, total bilirubin varied from 8 to 65 µmol/L (0.4-3.8 mg/dL) by different routine analyzers, with direct bilirubin ≤4 µmol/L (0.2 mg/dL). There was a positive correlation between total bilirubin difference and plasma eltrombopag concentration (r = 0.679), and spike-in experiments demonstrated that Beckman AU and Doumas reference methods were susceptible to positive interference. HPLC can quantify bilirubin after separating eltrombopag, and results suggest different analyzers are affected to varying degrees by eltrombopag and its metabolites. Conclusions Eltrombopag and its metabolites can cause positive interference to the spectrophotometric measurements of total bilirubin. Accurate measurements of total bilirubin may improve our understanding of the prevalence of hyperbilirubinemia in patients on eltrombopag therapy.

First-in-Human Study of AG10, a Novel, Oral, Specific, Selective, and Potent Transthyretin Stabilizer for the Treatment of Transthyretin Amyloidosis: A Phase 1 Safety, Tolerability, Pharmacokinetic, and Pharmacodynamic Study in Healthy Adult Volunteers.

AG10 is a novel, potent, and selective oral transthyretin (TTR) stabilizer being developed to treat TTR amyloidosis (ATTR). This randomized, double-blind, placebo-controlled study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics (ex vivo stabilization) of orally administered AG10 in healthy adult volunteers. Both mutant and wild-type ATTR are underdiagnosed diseases with limited therapeutic options. As TTR amyloidogenesis is initiated by dissociation of TTR tetramers destabilized due to inherited mutations or aging, AG10 is designed to treat the disease at its source. Four single and three multiple ascending dose levels of AG10 or matching placebo were orally administered. Safety and tolerability were assessed by vital signs, electrocardiogram, adverse events, and clinical laboratory tests. Pharmacokinetics were measured using a validated bioanalytical assay. Pharmacodynamics were assessed via three pharmacodynamic assays of TTR stabilization. AG10 was uniformly well tolerated, and no safety signals of clinical concern were observed. Pharmacokinetic observations included time to maximum concentration <1 hour, dose-dependent maximum concentration and area under the plasma concentration-time curve, low intersubject variability, and half-life ∼25 hr. Complete (>90%) stabilization of TTR was observed across the entire dosing interval at steady state on the highest dose tested. Serum TTR levels, an in vivo reflection of TTR stabilization by AG10, increased from baseline following 12 days of dosing. AG10 appears to be safe and well tolerated in healthy adult volunteers and can completely stabilize TTR across the dosing interval, establishing clinical proof of concept. Based on these data, AG10 has the potential to be a safe and effective treatment for patients with either mutant or wild-type ATTR.

Novel spectrofluorimetric quantification of alogliptin benzoate in biofluids exploiting its interaction with 4-chloro-7-nitrobenzofurazan.

The direct determination of alogliptin benzoate (ALO) using fluorescence has not yet been accomplished because ALO cannot fluoresce naturally. Accordingly, it should be derivatized first with a fluorogenic reagent to enhance the sensitivity required for its bioanalysis. This method is the first spectrofluorimetric assay for ALO quantification exploiting the nucleophilic nature of its amino group to react with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer at pH 8.5 to produce a strong fluorescent compound that is excited at and emits at wavelengths 470 and 527 nm, respectively. Experimental variables concerning the conditions of reaction and fluorogenic intensity were carefully investigated and optimized. Linearity was from 1-250 ng ml-1 with a lower detection limit of 0.29 ng ml-1 and a lower quantification limit of 0.88 ng ml-1 . Validation of the current study was accomplished with mean per cent recovery of 100.62 ± 1.59 in tablets and 99.86 ± 0.82 in human plasma. Furthermore, the current method has been utilized in the bioanalysis of ALO in real rat plasma after oral administration with a simple specimen preparation. The developed method has proven to be a promising alternative method for ALO analysis in bioequivalence studies.

Effect of cyclosporine coadministration on the pharmacokinetics of eltrombopag in healthy volunteers.

PURPOSE: Eltrombopag is indicated in patients with severe aplastic anemia (SAA) refractory to prior immunosuppressive therapy. The combination of eltrombopag and immunosuppressive therapy (such as cyclosporine) is currently being evaluated in patients with treatment-naive SAA. Cyclosporine is a human breast cancer resistance protein (BCRP) inhibitor, and can potentially alter plasma exposure to eltrombopag, a BCRP substrate. This phase 1, open-label, randomized, 3-period, crossover study evaluated the effect of cyclosporine on the pharmacokinetics of eltrombopag in healthy adults. METHODS: Thirty-nine subjects were randomized to either single dose of eltrombopag 50 mg, cyclosporine 200 mg + eltrombopag 50 mg or cyclosporine 600 mg + eltrombopag 50 mg treatment groups. Eltrombopag pharmacokinetic parameters (Cmax, tmax, AUClast, AUCinf, %AUCex, t1/2, and CL/F) were determined using noncompartmental methods. RESULTS: Geometric mean AUCinf, AUClast, and Cmax, were decreased by 18, 20, and 25%, respectively, for cyclosporine 200 mg + eltrombopag and by 24, 22, and 39%, respectively, for cyclosporine 600 mg + eltrombopag groups compared to the eltrombopag alone group. The median tmax was prolonged by ~ 1 h in both coadministration treatments. The geometric mean t1/2 was ≈ 21, ≈ 24, and ≈ 26 h, respectively, in cyclosporine 200 mg + eltrombopag, cyclosporine 600 mg + eltrombopag and eltrombopag alone groups. All the treatments were safe and well-tolerated. No serious adverse event or death was reported during the study. CONCLUSION: These changes in exposure were not considered clinically meaningful as the dose of eltrombopag is adjusted using within-patient dose titration based on platelet counts.

Kinetic time courses of lambda-cyhalothrin metabolites after dermal application of Matador EC 120 in volunteers.

A controlled kinetic study was conducted in volunteers dermally exposed to the widely used lambda-cyhalothrin pyrethroid pesticide to document the time courses of relevant biomarkers of exposure, in order to better assess biomonitoring data in workers. Matador® EC120 formulation (120 g/l) was applied on 40 cm2 of the forearm at a 0.25 mg/kg dose of lambda-cyhalothrin and left without occlusion or washing for 6 h. The application site was then washed thoroughly with soap and water. The kinetic time courses of cis-3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropane carboxylic acid (CFMP) and 3-phenoxybenzoic acid (3-PBA) metabolites were determined in plasma and urine up to 84 h post-application. Results show that the fraction of lambda-cyhalothrin absorbed in the body was rapidly cleared following dermal contact. According to CFMP and 3-PBA plasma profiles, calculated mean apparent absorption half-lives (t1/2) were 3 and 7.3 h, respectively, and corresponding mean apparent elimination t1/2 were 11.2 and 7.6 h. These differences suggest some metabolism at the site-of-entry and storage of metabolites by the dermal route. Toxicokinetic parameters calculated from urinary profiles confirm the values of absorption and elimination rates. Metabolites were almost completely excreted over the 84-h period post-application and, on average, 0.12 and 0.08% of the applied lambda-cyhalothrin dose was recovered in the urine as CFMP and 3-PBA, respectively, indicating a low dermal absorption fraction of this pyrethroid. This study showed the potential use of CFMP and 3-PBA biomarkers for the assessment of dermal exposure to lambda-cyhalothrin pyrethroid.

Human metabolism and kinetics of tri-(2-ethylhexyl) trimellitate (TEHTM) after oral administration.

Tri-(2-ethylhexyl) trimellitate (TEHTM) is a plasticizer for PVC material and is used for medical devices as an alternative to di-(2-ethylhexyl) phthalate. As plasticizers are known to migrate easily into contact liquids, exposure of patients to TEHTM is highly probable. In the present study, human metabolism pathways of TEHTM and its elimination kinetics were investigated. For that purpose, four healthy volunteers were orally exposed to a single dose of TEHTM. TEHTM and its postulated primary metabolites were investigated in blood samples (up to 48 h after exposure), and in urine samples (collected until 72 h after exposure) using liquid chromatography tandem mass spectrometry (LC-MS/MS). TEHTM was found to be regioselectively hydrolyzed to its diesters di-2-(ethylhexyl) trimellitates (1,2-DEHTM, 2,4-DEHTM) with maximum blood concentrations at 3-h post-exposure, and to its monoester isomers mono-2-(ethylhexyl) trimellitates (1-MEHTM, 2-MEHTM) with peak blood concentrations 5-h post-exposure. For the elimination of investigated urinary metabolites, biphasic elimination kinetics was observed. The most dominant urinary biomarker was found to be 2-MEHTM (2-mono-(2-ethylhexyl) trimellitate), followed by several specific secondary metabolites. All in all, approximately 5.8% of the orally administered dose was recovered in urine over a period of 72 h, indicating a comparatively low resorption rate of TEHTM in humans in combination with an apparently rather slow metabolism and excretion rate. In fact, TEHTM and selected metabolites were still detectable in blood and urine 48-h and 72-h post-exposure, respectively. This study is the first to elucidate TEHTM metabolism pathways in humans and to identify metabolites of TEHTM in blood and urine by usage of especially designed human biomonitoring methods. Powerful tools for exposure monitoring and risk assessment of TEHTM are therewith available for future research.

Therapeutic Doses of Eltrombopag do not Inhibit Hepatic BCRP in Healthy Volunteers: Intravenous Ceftriaxone as a Model.

PURPOSE: Ceftriaxone elimination occurs through breast cancer resistance transporter (BCRP) and multidrug resistance-associated protein 2 (MRP-2) which are expressed on the canalicular membrane of hepatocytes. Eltrombopag, a thrombopoetin receptor agonist used in the treatment of immune thrombocytopenic purpura, is reported in in vitro studies as an inhibitor of intestinal BCRP but not an inhibitor of hepatic BCRP. Thus, the present study evaluates the effect of therapeutic doses of eltrombopag on the clinical pharmacokinetics of intravenous ceftriaxone. METHODS: Healthy adult (n=12) were treated with oral doses of eltrombopag (0, 25 or 50 mg) 28 and 4 h prior to intravenous ceftriaxone administration (1g). Serial blood samples were collected up to 48 h after ceftriaxone administration and plasma samples were analysed by LC-MS/MS using 50 µL aliquots (total concentration) and 100 µL (unbound concentration). RESULTS: A method to analyze total and unbound ceftriaxone in plasma using LC-MS/MS was developed and validated with linearity from 1 to 200 µg/mL. Both methods are sensitive, precise and accurate with coefficients of variation less than 15% in the study of inter- and intra-assay precision and accuracy. Ceftriaxone pharmacokinetics in healthy adults were described using a bicompartmental model, with a mean clearance of 0.96 L/h (CI95% 0.71-1.20) and AUC0-∞of 1106 mg.h/mL (CI95% 811-1400) for volunteers that received only ceftriaxone; clearance of 0.95 L/h (CI95% 0.77-1.13) and AUC0-∞ of 1083 mg.h/mL (CI95% 876-1290) for volunteers that received ceftriaxone plus 25 mg of eltrombopag and clearance of 0.96 L/h (CI95% 0.74-1.19) and AUC0-∞ of 1072 mg.h/mL (CI95% 872-1273) for volunteers that received ceftriaxone plus 50 mg of eltrombopag. CONCLUSIONS: The results do not support the existence of a clinical pharmacokinetic drug interaction involving hepatic BCRP in human subjects receiving intravenous ceftriaxone and oral eltrombopag. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Eltrombopag-Induced Acute Liver Failure in a Pediatric Patient: A Pharmacokinetic and Pharmacogenetic Analysis.

Eltrombopag is an oral thrombopoietin receptor agonist approved for the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP), who are more than 1 year old, and show poor response to first-line therapy. ITP is a hematological disorder characterized by isolated thrombocytopenia in the absence of secondary causes or disorders. Eltrombopag is generally well tolerated in the pediatric population; therefore, therapeutic drug monitoring (TDM) is not usually performed in clinical practice.We presented the case study of a 3-year-old girl with chronic ITP. She arrived in the pediatric intensive care unit with acute liver failure due to eltrombopag toxicity despite taking the standard drug dosage. A very high eltrombopag plasma concentration, indicating drug toxicity, was found through TDM. The patient also carried the allelic variations that are involved in drug metabolism [CYP2C8 and UDP glucuronosyltransferase (UGT) 1A1 (UGT1A1)] and drug cellular transportation [ABCG2 (ATP-binding cassette G2)]. This observation highlights the importance of using TDM and pharmacogenetic approaches to manage patients' unusual complications associated with standard pharmacological treatment regimens.

Simultaneous determination of AM80 (tamibarotene) and WJD-A-1 in rat plasma by ultra high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

A compound (WJD-A-1) was previously reported as a candidate prodrug of Am80 (tamibarotene), which was approved in Japan in 2005 as a therapeutic agent for recurrent refractory acute promyelocytic leukaemia. A rapid, selective and sensitive ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the first time to simultaneously determine WJD-A-1 and its major phase-I metabolites AM80 in rat plasma. After a simple sample preparation procedure by protein precipitation with methanol and acetonitrile, WJD-A-1, AM80 and the internal standard were chromatographed on an ACQUITY UPLCTM BEH C18 column. The mobile phase consisted of methanol-0.1% formic acid (80:20, v/v) and the flow rate was 0.20 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. Each plasma sample was chromatographed within 2.6 min. The linear calibration curves for WJD-A-1 and the AM80 were obtained in the concentration range of 5.40-5.40 × 103 and 5.08-5.08 × 103 ng/mL, respectively (r ≥ 0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were less than 8% and the accuracy (relative error, RE) was within ±6.8%, determined from quality control (QC) samples for the analytes. The method herein described was fully validated and successfully applied to pharmacokinetic study of WJD-A-1 following an intravenous administration of 300 µg/kg WJD-A-1 to rats.

Pharmacokinetic and bioequivalence study of a telmisartan/S-amlodipine fixed-dose combination (CKD-828) formulation and coadministered telmisartan and S-amlodipine in healthy subjects.

PURPOSE: A new fixed-dose combination (FDC) formulation of telmisartan 80 mg and S-amlodipine 5 mg (CKD-828) has been developed to increase convenience (as only one tablet is required per day) and improve treatment compliance. METHODS: The pharmacokinetic characteristics and tolerability of an FDC of telmisartan and S-amlodipine were compared to those after coadministration of the individual agents in this randomized, open-label, single-dose, two-way, four-period, crossover study. To analyze the telmisartan and S-amlodipine plasma concentrations using a validated liquid chromatography-tandem mass spectrometry method, serial blood samples were collected up to 48 hours post-dose for telmisartan and 144 hours post-dose for S-amlodipine, in each period. RESULTS: Forty-eight healthy subjects were enrolled, and 43 completed the study. The mean peak plasma concentration (Cmax) and the area under the plasma concentration-time curve from time 0 to the last measurement (AUC0-t) values of telmisartan were 522.29 ng/mL and 2,475.16 ng·h/mL for the FDC, and 540.45 ng/mL and 2,559.57 ng·h/mL for the individual agents concomitantly administered, respectively. The mean Cmax and AUC0-t values of S-amlodipine were 2.71 ng/mL and 130.69 ng·h/mL for the FDC, and 2.74 ng/mL and 129.81 ng·h/mL for the individual agents concomitantly administered, respectively. The geometric mean ratio (GMR) and 90% confidence interval (CI) for the telmisartan Cmax and AUC0-t (FDC of telmisartan and S-amlodipine/concomitant administration) were 0.8509 (0.7353-0.9846) and 0.9431 (0.8698-1.0226), respectively. The GMR and 90% CI for the S-amlodipine Cmax and AUC0-t (FDC/concomitant administration) were 0.9829 (0.9143-1.0567) and 0.9632 (0.8798-1.0546), respectively. As the intrasubject variability of the Cmax for telmisartan administered individually was 42.94%, all 90% CIs of the GMRs fell within the predetermined acceptance range. Both treatments were well tolerated in this study. CONCLUSION: CKD-828 FDC tablets were shown to be bioequivalent to coadministration of the individual agents with the respective strength, in healthy subjects under fasting conditions. There was no significant difference in safety profile between the two treatments.

A simple LC-MS/MS method for determination of deferasirox in human plasma: Troubleshooting of interference from ferric ion in method development and its application.

As an orally active iron chelator, deferasirox forms its ion complexes in the prepared plasma samples and LC-MS mobile phase where ferric ion exists, and then comparing with the nominal concentration level, a lower detected concentration level of deferasirox would be obtained after LC-MS analysis, if no proper treatment was adopted. Meanwhile, the phenomenon would be observed that multiple repeat injections of the same deferasirox plasma sample in the same tube would show the lower and lower detected concentration levels of deferasirox, which caused by more and more ferric ions from the injection needle dissolved in the sample solution as multiple repeated injections. The addition of a proper concentration of EDTA in the mobile phase and the sample will competitively inhibit deferasirox from complexing with ferric ion, and prevent the decrease of deferasirox concentration. In this paper, an LC-MS/MS method was developed and validated for the determination of deferasirox in human plasma. To achieve the protein precipitation, the analytes were extracted from aliquots of 200 µL human plasma with acetonitrile. Chromatographic separation was performed on an ODS-C18 column with the mobile phase consisted of methanol and 0.1% formic acid containing 0.04 mM ethylenediamine tetraacetate dihydrate (EDTA) (80:20, v/v) at a flow rate of 0.5 mL/min. Deferasirox and the internal standard (IS, mifepristone) were detected using electrospray ionization in positive ion multiple reaction monitoring mode by monitoring the precursor-to-product ion transitions m/z 374.2 → 108.1 for deferasirox and m/z 430.1 → 372.2 for the IS. The method exhibited good linearity over the concentration range of 0.04-40 µg/mL for deferasirox. The method was successfully applied to a pharmacokinetic study in 10 Chinese healthy volunteers after oral administration of deferasirox.

Conversion and pharmacokinetics profiles of a novel pro-drug of 3-n-butylphthalide, potassium 2-(1-hydroxypentyl)-benzoate, in rats and dogs.

Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB) is a novel pro-drug of 3-n-butylphthalide (dl-NBP) that is used to treat ischemic stroke. Currently, dl-PHPB is in phase II-III clinical trials in China. In this study, we investigated the conversion and pharmacokinetics profiles of dl-PHPB in vitro and in vivo. The conversion of dl-PHPB to dl-NBP was pH- and calcium-dependent, and paraoxonase was identified as a major enzyme for the conversion in rat plasma. The pharmacokinetics, tissue distribution and excretion of dl-PHPB were studied and compared with equal-molar doses of dl-NBP in rats and dogs. The in vivo studies showed that dl-PHPB could be quickly and completely converted to dl-NBP. The plasma concentration-time course of converted dl-NBP after intravenous dl-PHPB administration was nearly the same as that after equal-molar dl-NBP. The Cmax and AUC of dl-NBP after oral dl-PHPB administration in rats and dogs were higher by 60% and 170%, respectively, than those after oral dl-NBP administration. Analysis of the tissue distribution of dl-PHPB revealed that converted dl-NBP was primarily distributed in fat, the brain and the stomach. In the brain, the levels of dl-NBP were relatively higher after dl-PHPB treatment by orally than after treatment with equal-molar dl-NBP. Approximately 3%-4% of dl-NBP was excreted within 72 h after dosing with dl-PHPB or dl-NBP, but no dl-PHPB was detected in urine or feces excrements. Our results demonstrate that the conversion of dl-PHPB is fast after oral or intravenous administration. Furthermore, the bioavailability of dl-PHPB was obviously better than that of dl-NBP.