Time Of Last Quantifiable Concentration Research Articles

Phase 1 pharmacokinetic and safety study of soticlestat in participants with mild or moderate hepatic impairment or normal hepatic function.

This phase 1, open-label, three-arm study (NCT05098054) compared the pharmacokinetics and safety of soticlestat (TAK-935) in participants with hepatic impairment. Participants aged ≥18 to <75 years had moderate (Child-Pugh B) or mild (Child-Pugh A) hepatic impairment or normal hepatic function (matched to hepatic-impaired participants by sex, age, and body mass index). Soticlestat was administered as a single oral 300 mg dose. Pharmacokinetic parameters of soticlestat and its metabolites TAK-935-G (M3) and M-I were assessed and compared by group. The incidence of treatment-emergent adverse events (TEAEs) and other safety parameters were also monitored. The pharmacokinetic analyses comprised 35 participants. Participants with moderate hepatic impairment had lower proportions of bound and higher proportions of unbound soticlestat than participants with mild hepatic impairment and normal hepatic function. Total plasma soticlestat pharmacokinetic parameters (maximum observed concentration [Cmax], area under the concentration-time curve from time 0 to time of last quantifiable concentration [AUClast], and AUC from time 0 to infinity [AUC∞]) were approximately 115%, 216%, and 199% higher with moderate and approximately 45%, 35%, and 30% higher with mild hepatic impairment, respectively, than healthy matched participants. Moderate hepatic impairment decreased the liver's ability to metabolize soticlestat to M-I; glucuronidation to M3 was also affected. Mild hepatic impairment resulted in a lower total plasma M-I exposure, but glucuronidation was unaffected. TEAEs were similar across study arms, mild, and no new safety findings were observed. A soticlestat dose reduction is required for individuals with moderate but not mild hepatic impairment.

Effects of Food, Gastric Acid Reduction, and Strong CYP3A Induction on the Pharmacokinetics of Tasurgratinib, a Novel Selective Fibroblast Growth Factor Receptor Inhibitor.

We conducted this three-part study in healthy subjects to investigate the pharmacokinetics of tasurgratinib (orally available selective inhibitor of fibroblast growth factor receptor 1-3) and M2 (its major metabolite) under different conditions. In Part A, subjects received tasurgratinib 35 mg either fed with a high-fat meal or fasted. In Parts B and C, subjects received tasurgratinib 35 mg alone or with either rabeprazole (acid-reducing agent) 20 mg (Part B) or rifampin (strong CYP3A inducer) 600 mg (Part C). Primary endpoints were maximum concentration (Cmax), and areas under the plasma concentration-time curve to time of last quantifiable concentration (AUC(0-t)) and extrapolated to infinite time (AUC(0-inf)). Forty-two subjects were enrolled, 14 each into Parts A, B, and C. In Part A, administration of tasurgratinib with a high-fat meal resulted in 33% reduction in Cmax and ∼23% reduction in AUC(0-t) and AUC(0-inf) of tasurgratinib, and 47% reduction in Cmax with ∼30% reduction in AUC(0-t) and AUC(0-inf) of M2. In Part B, co-administration of rabeprazole at steady state resulted in no/weak interaction with tasurgratinib (∼8% increase in AUC(0-t) and AUC(0-inf) without an effect on Cmax) and M2 (∼18% increase in AUC(0-t) and AUC(0-inf) without an effect on Cmax). In Part C, co-administration of rifampin at steady state resulted in a weak interaction with tasurgratinib (∼16% reduction in AUC(0-t) and AUC(0-inf)) and M2 (∼12% reduction in AUC(0-t) and AUC(0-inf)). Administration of tasurgratinib with a high-fat meal appeared to reduce systemic exposure of tasurgratinib, however co-administration with an acid-reducing agent or a CYP3A inducer had a minimal impact on pharmacokinetics.

Safety, Tolerability, and Pharmacokinetics of Single- and Multiple-Ascending Doses of Sunobinop in Healthy Participants.

Sunobinop is an investigational, potent, selective partial agonist at the nociceptin/orphanin FQ peptide receptor in vitro. Three phase 1 studies were conducted to evaluate the safety, tolerability, and pharmacokinetics (PK) of escalating single- and multiple-dose administration of sunobinop in healthy participants. Study 1 was a randomized, double-blind, placebo-controlled, single-ascending dose study. Study 2 was a randomized, double-blind, placebo-controlled, multiple-ascending dose study. Study 3 was a randomized, open-label, single-dose, 4-way crossover study of oral and sublingual sunobinop comparing morning (AM) and bedtime (PM) administration. Seventy participants were included. Systemic exposure (peak plasma concentration [Cmax], area under the plasma concentration-time curve from time 0 to the time of last quantifiable concentration [AUC0-t], and area under the plasma concentration-time curve from time 0 extrapolated to infinity [AUCinf]) of sunobinop was characterized by dose proportionality from 0.6 to 2mg and increased less than proportionally from 3 to 30mg. The PKs of sunobinop were similar, regardless of AM or PM administration, for both the oral and sublingual formulations. The majority of absorbed sunobinop was excreted unchanged in the urine within 8 hours of dosing, thereby showing rapid elimination with no appreciable accumulation following 14 consecutive days of once-daily dosing and suggesting exclusive renal elimination. Most treatment-emergent adverse events (TEAEs) were mild in severity; 1 severe TEAE occurred and all TEAEs resolved by the end of the studies. Sunobinop was generally well-tolerated and safe across the range of doses evaluated and presents a clinical profile suitable for continued development.

A Randomized, Single-Dose, Parallel-Controlled Phase 1 Clinical Comparison of an Omalizumab Biosimilar Candidate with Reference Omalizumab in Healthy Chinese Male Volunteers.

This study evaluated the bioequivalence of omalizumab, a humanized monoclonal antibody against immunoglobulin-E (IgE), with one of its biosimilar candidates. The study was designed as a randomized, double-blind, parallel-controlled trial. A total of subjects who met the inclusion criteria and did not meet the exclusion criteria were dynamically randomly assigned to receive the test drug or the reference drug with a single subcutaneous injection of 150mg by the minimization method. The test group and the reference group had similar demographic characteristics and baseline characteristics of total IgE. The 90% confidence interval of the geometric average ratio of the area under the serum concentration-time curve from the time 0 to the time of last quantifiable concentration, the area under the serum concentration curve from time 0 to infinity, and the maximum observed serum concentration between the 2 groups were within 80%-125%, showing bioequivalence. The changing trend of total and free IgE in the 2 groups was similar after administration, proving the pharmacodynamic similarity. The 2 groups had no significant difference in the positive rate of antidrug antibodies, and the total positive rate of neutralizing antibodies was 0. The incidence of treatment-emergent adverse events and treatment-related adverse events were similar between the 2 groups, with no serious adverse events. This study shows that the test drug had similar pharmacokinetics, immunogenicity, and safety to the reference omalizumab in healthy male subjects.

Pooled analysis of three pharmacokinetic studies comparing biosimilar MB02 and reference bevacizumab.

The aim of this study was to add robustness and provide further evidence on the bioequivalence, safety and immunogenicity between MB02 and reference bevacizumab. No similar study has been performed before with a biosimilar monoclonal antibody. Population analysis by pooling data from three independent pharmacokinetic (PK) studies was performed. The studies had a single-dose, double-blind, three-arm, parallel-group design and two studies, MB02-A-02-17 and MB02-A-05-18, compared MB02 to EU- and US-bevacizumab in Caucasian subjects, while study MB02-A-04-18 compared MB02 and EU-bevacizumab in Japanese participants. Primary endpoints included maximum observed serum concentration (Cmax ), area under the serum concentration-time curve (AUC) from time zero and extrapolated to infinity (AUC0-∞ ) and AUC from time zero to the time of last quantifiable concentration (AUC0-t ). Secondary endpoints included other PK parameters, safety and immunogenicity. A sensitivity analysis using actual protein concentration as a correction factor was applied to primary PK parameters. Point estimates and 90% confidence intervals for the geometric mean ratios of primary PK parameters for MB02, EU- and US-bevacizumab were all contained within the predefined bioequivalence margins (80%-125%) for all pairwise comparisons. The same results for all pairwise comparisons were observed when protein-corrected primary PK parameters were analyzed. Safety and immunogenicity were similar between MB02 and the EU- and US-reference bevacizumab in healthy subjects. This pooled analysis of three comparable PK studies further supports the bioequivalence of biosimilar MB02 to EU- and US-reference bevacizumab. No clinically meaningful differences in safety or immunogenicity were observed.

Investigation of the Differences in the Pharmacokinetics of CYP2D6 Substrates, Desipramine, and Dextromethorphan in Healthy African Subjects Carrying the Allelic Variants CYP2D6*17 and CYP2D6*29, When Compared with Normal Metabolizers.

This study investigated the differences in the pharmacokinetics (PK) of dextromethorphan and desipramine in healthy African volunteers to understand the effect of allelic variants of the human cytochrome P450 2D6 (CYP2D6) enzyme, namely the diplotypes of CYP2D6*1/*2 (*1*1, *1*2, *2*2) and the genotypes of CYP2D6*17*17 and CYP2D6*29*29. Overall, 28 adults were included and split into 3 cohorts after genotype screening: CYP2D6*1/*2 (n=12), CYP2D6*17*17 (n=12), and CYP2D6*29*29 (n=4). Each subject received a single oral dose of dextromethorphan 30mg syrup on day1 and desipramine 50mg tablet on day8. The PK parameters of area under the plasma concentration-time curve from time of dosing to time of last quantifiable concentration (AUClast), and extrapolated to infinity (AUCinf), and the maximum plasma concentration (Cmax) were determined. For both dextromethorphan and desipramine, AUCinf and Cmax were higher in subjects of the CYP2D6*29*29 and CYP2D6*17*17 cohorts, as compared with subjects in the CYP2D6*1/*2 diplotype cohort and with normal metabolizers from the literature. All PK parameters, including AUCinf, Cmax, and the elimination half-life, followed a similar trend: CYP2D6*17*17>CYP2D6*29*29>CYP2D6*1/*2. The plasma and urinary drug/metabolite exposure ratios of both drugs were higher in subjects of the CYP2D6*17*17 and CYP2D6*29*29 cohorts, when compared with subjects in the CYP2D6*1/*2 diplotype cohort. All adverse events were mild, except in 1 subject with CYP2D6*17*17 who had moderately severe headache with desipramine. These results indicate that subjects with CYP2D6*17*17 and CYP2D6*29*29 genotypes were 5-10 times slower metabolizers than those with CYP2D6*1/*2 diplotypes. These findings suggest that dose optimization may be required when administering CYP2D6 substrate drugs in African patients. Larger studies can further validate these findings.

Effects of rifampicin on antineoplastic drug pyrotinib maleate pharmacokinetics in healthy subjects.

Pyrotinib (PTN), an irreversible EGFR/HER2 dual tyrosine kinase inhibitor used for treating HER2-positive breast cancer, is primarily metabolized by cytochrome P450 (CYP)3A4 isozyme. Rifampicin (RIF) is a strong index CYP3A4 inducer. Therefore, the study aimed to elucidate the effect of RIF on PTN pharmacokinetics (PK) in Chinese healthy volunteers. This phase I, open-label study investigated the effects of steady-state RIF administration on single-dose PK of PTN. 18 healthy participants were enrolled in this trial, who received a single oral dose of 400mg of PTN on days 1 and 13, and were administrated with RIF 600mg qd on days 6 through 16. RIF was administrated on an empty stomach, PTN were administrated orally in the morning 30min after the start of the standard meal. Serial PK samples for PTN were collected on days 1 and days 13. Safety assessments were performed via clinical laboratory tests throughout the study. 18 subjects were enrolled and 16 completed the study. RIF significantly reduced PTN exposure: Geometric least-squares mean ratios (90% CI) for PTN + RIF versus PTN alone were 0.04 (0.034,0.049), 0.04 (0.037,0.054), and 0.11 (0.09,0.124) for area under the curve from time zero to time of last quantifiable concentration (AUC0 - t), area under the curve from time zero to infinity (AUC0-∞ ), and maximum observed plasma concentration(Cmax), respectively. PTN alone and co-administered with RIF was well tolerated. The exposure of PTN was significantly affected by the action of RIF. The findings suggest that concomitant strong CYP3A4 inducers should be avoided during PTN treatment. Concurrent administration of PTN and RIF was well tolerated.

Bioavailability, safety and tolerability of intravenous brivaracetam in healthy Japanese participants

We characterised the bioavailability, safety, and tolerability of brivaracetam 100 mg intravenous bolus and 15-min infusion versus oral reference tablet in 24 healthy Japanese participants. In this randomised, open-label, three-period crossover study, participants received three 100 mg single doses of brivaracetam, intravenous bolus, infusion, and oral tablets. Maximum plasma concentration (Cmax), area under the plasma concentration-time curve from time zero to the time of last quantifiable concentration (AUCt), and area under the plasma concentration-time curve extrapolated to infinity (AUCinf), were compared using analysis of variance following logarithmic transformation. Bioavailability comparisons were based on the 90% confidence intervals (CIs) around the geometric least squares means ratios (intravenous:oral). Safety and tolerability were monitored throughout the study. The 90% CIs around AUCt and AUCinf ratios were entirely contained within the bioequivalence limits (0.80–1.25), but Cmax was outside the limits (90% CI: 1.77–2.08 and 1.44–1.70 for intravenous bolus and infusion, respectively). All participants completed the study. Brivaracetam was well tolerated. Because response to brivaracetam in epilepsy is related to exposure (AUC), no dose adjustment is warranted when switching from oral to intravenous dosing. However, investigations are needed to assess the safety and tolerability of intravenous administration in Japanese patients with epilepsy.

Pharmacokinetic Properties of S-oxiracetam After Single and Multiple Intravenous Infusions in Healthy Volunteers.

As a chiral drug, oxiracetam (ORT) can exist in two different isomeric forms: S-oxiracetam (S-ORT) and R-oxiracetam (R-ORT). S-ORT has emerged as a promising nootropic drug with the potential to treat brain injury and the resulting loss of neural function, memory and mental impairment as assessed by studies in various animal models. However, limited data are available on the pharmacokinetics of S-ORT in humans, so the present study was designed to evaluate the safety and pharmacokinetic profile of S-ORT in healthy volunteers. In part 1, subjects were intravenously administered single ascending dose (2.0, 4.0 and 8.0 g) S-ORT. In part 2, subjects were treated at a single intravenous infusion dose of 3.0 g S-ORT or 6.0 g racemic ORT using a two-sequence, two-period crossover design. In part 3, subjects were intravenously injected with 4.0 g S-ORT once a day for 7 days. Blood and urine samples were collected to evaluate the pharmacokinetic parameters and urine excretion rate. The safety profile of the drug was also evaluated throughout the study. Fifty-two subjects (30 in part 1, 12 in part 2, 10 in part 3) completed the study; only one subject displayed a mild adverse event, which possibly was treatment related, and no serious adverse event occurred. In part 1 for a single dose of 2.0, 4.0 and 8.0 g, the maximum concentration (Cmax) values were 111.28±18.99, 230.76±29.16 and 352.67±42.94 μg/ml, respectively; the values of area under the plasma concentration-time curve (AUC) from time zero to the time of last quantifiable concentration (AUC0-t) were 267.09±59.66, 524.50 ±72.87 and 822.68±95.21 μg·h/ml, respectively; the AUC from 0 h to infinity (AUC0-∞) values were 274.72±61.65, 536.06±78.13 and 832.07±96.91 μg·h/ml, respectively. The urine excretion rate of the unchanged drug was approximately 60%. After consecutive administration of S-ORT for 7 days, the accumulation index was 1.05±0.08. The plasma drug concentration-time curves for both S-ORT and R-oxiracetam (R-ORT) were almost identical. S-ORT was well tolerated, and no serious adverse events occurred in 2.0, 4.0 and 8.0 g in single- and 4.0 g in multiple-dose studies. S-ORT showed dose linearity with increasing doses and no drug accumulation after 7 days of continuous administration was observed.

Evaluation of drug-drug interaction potential between omecamtiv mecarbil and rosuvastatin, a BCRP substrate, with a clinical study in healthy subjects and using a physiologically-based pharmacokinetic model.

Omecamtiv mecarbil (OM) is a novel cardiac myosin activator in development for the treatment of heart failure. In vitro, OM is an inhibitor of BCRP. Rosuvastatin, a BCRP substrate, is one of the most commonly prescribed medications in patients with heart failure. The potential for a pharmacokinetic (PK) drug‐drug interaction (DDI) was investigated, specifically to determine whether a single 50 mg dose of OM would impact the PKs of a single 10 mg dose of rosuvastatin in an open‐label study in 14 healthy subjects. The ratios of the geometric least‐square means (90% confidence intervals [CIs]) of rosuvastatin co‐administered with OM compared to rosuvastatin alone were 127.1% (90% CI 113.8–141.9), 132.8% (90% CI 120.7–146.1), and 154.2% (90% CI 132.8–179.1) for area under the plasma‐concentration time curve from time zero to infinity (AUCinf), area under the plasma‐concentration time curve from time zero to time of last quantifiable concentration (AUClast), and maximum observed plasma concentration (Cmax), respectively. Whereas the DDI study with rosuvastatin was conducted with the co‐administration of a single dose of OM, in the clinical setting, patients receive OM at doses of 25, 37.5, or 50 mg twice daily (b.i.d.). Hence, to extrapolate the results of the DDI study to a clinically relevant scenario of continuous b.i.d. dosing with OM, physiologically‐based pharmacokinetic (PBPK) modeling was performed to explore the potential of BCRP inhibition following continuous b.i.d. dosing of OM at the highest 50 mg dose. Modeling results indicated that following 50 mg b.i.d. dosing of OM, the predicted ratios of the geometric means (90% CIs) for rosuvastatin AUCinf and Cmax were 1.18 (90% CI 1.16–1.20) and 2.04 (90% CI 1.99–2.10), respectively. Therefore, these results suggest that OM, following multiple dose administration, is a weak inhibitor of BCRP substrates and is in accordance with that observed in the single dose OM DDI clinical study.

A pharmacokinetics study of proposed bevacizumab biosimilar MYL-1402O vs EU-bevacizumab and US-bevacizumab

PurposeBevacizumab is a recombinant humanized monoclonal antibody that inhibits vascular endothelial growth factor-specific angiogenesis in some cancers. MYL-1402O is a proposed bevacizumab biosimilar.MethodsThe primary objective of this single-center, randomized, double-blind, three-arm, parallel-group, phase 1 study in healthy male volunteers was to evaluate bioequivalence of MYL-1402O to EU and US-reference bevacizumab, and EU-reference bevacizumab to US-reference bevacizumab. The primary pharmacokinetic parameter was area under the serum concentration–time curve from 0 extrapolated to infinity (AUC0–∞). Pharmacokinetic parameters were analyzed using general linear models of analysis of variance. Secondary endpoints included safety and tolerability.ResultsOf 111 enrolled subjects, 110 were included in the pharmacokinetic analysis (MYL-1402O, n = 37; EU-reference bevacizumab, n = 36; US-reference bevacizumab, n = 37). Bioequivalence was demonstrated between MYL-1402O and EU-reference bevacizumab, MYL-1402O and US-reference bevacizumab, and between EU- and US-reference bevacizumab where least squares mean ratios of AUC0–∞ were close to 1, and 90% CIs were within the equivalence range (0.80–1.25). Secondary pharmacokinetic parameters (AUC from 0 to time of last quantifiable concentration [AUC0–t], peak serum concentration [Cmax], time to Cmax, elimination rate constant, and elimination half-life) were also comparable, with 90% CIs for ratios of AUC0–t and Cmax within 80–125%. Treatment-emergent adverse events were similar across all three treatment groups and were consistent with clinical data for bevacizumab.ConclusionMYL-1402O was well tolerated and demonstrated pharmacokinetic and safety profiles similar to EU-reference bevacizumab and US-reference bevacizumab in healthy male volunteers. No new significant safety issues emerged (ClinicalTrials.gov, NCT02469987; ClinicalTrialsRegister.eu EudraCT, 2014-005621-12; June 12, 2015).

A randomized, open-label, crossover study to compare the safety and pharmacokinetics of two tablet formulations of tenofovir (tenofovir disoproxil and tenofovir disoproxil fumarate) in healthy subjects.

This study was performed to compare the pharmacokinetic properties and assess bioequivalence for the test formulation (HUG116 tablet; tenofovir disoproxil) and reference formulation (Viread tablet; tenofovir disoproxil fumarate). A randomized, open-label, single-dosing, two-treatment, two-period, two-sequence cross-over study was conducted in 50 healthy subjects. All subjects were randomly assigned to one of the two sequences, and they received a single dose of test or reference formulation in the first period and the alternative formulation during the next period under fasting conditions. Serial blood samples for pharmacokinetic evaluation were collected up to 72hours post dose, and the pharmacokinetic parameters were estimated by noncompartmental methods. Throughout the study, tolerability was assessed based on adverse events, vital signs, and clinical laboratory tests. The test formulation showed similar pharmacokinetic profiles to those of the reference formulation. The geometric mean ratio and 90% confidence interval (CI) of the test formulation to the reference formulation for maximum plasma concentration (Cmax) was 0.93 (0.87-0.99), and the corresponding value for the area under the concentration-time curve from time zero to time of last quantifiable concentration (AUCt) was 0.94 (0.89-0.99). Both CIs were within the conventional bioequivalence range of 0.8-1.25. The tolerability profile was not significantly different between the test and reference formulations. This study found that the PKs of the test formulation (HUG116 tablet; tenofovir disoproxil) and reference formulation (Viread tablet; tenofovir disoproxil fumarate) were similar, and the test formulation met the regulatory criteria for assuming bioequivalence with the reference formulation.

Pharmacokinetic/pharmacodynamic and safety study of a single dose of evolocumab 140 mg in healthy Chinese subjects.

Evolocumab, a human monoclonal antibody that binds to proprotein convertase subtilisin/kexin type 9 (PCSK9), markedly reduces low-density lipoprotein cholesterol (LDL-C). Here we characterize the pharmacokinetics, pharmacodynamics, safety, and tolerability of evolocumab manufactured at a new site administered in healthy Chinese subjects. This phase 1 study of a single subcutaneous 140-mg dose of evolocumab was conducted in healthy subjects of Chinese descent residing in Hong Kong. Subjects were followed through day 85. 20 subjects (all men) were enrolled. Mean (SD) age was 26.6 (8.5) years; baseline LDL-C was 2.4 (0.7) mmol/L. Mean (SD) evolocumab maximum serum concentration (Cmax) was 14.1 (5.0) μg/mL; area under the serum drug concentration-time curve from time 0 to time of last quantifiable concentration (AUClast) was 178 (80) day×μg/mL; AUC from time 0 to infinity (AUCinf) was 187 (80) day×μg/mL; terminal half-life was 5.95 (1.76) days; median time to reach Cmax (tmax) was 4.0 days. Maximum LDL-C decrease (-57.5%) was observed on day 15 and recovered to baseline by day 57. The most common adverse events (AEs) were nasal congestion (20%), oropharyngeal pain (15%), sneezing (15%), cough (10%), upper respiratory tract infection (10%), and diarrhea (10%). Most AEs were isolated incidences of mild severity, with no serious or treatment-related events. No anti-evolocumab antibodies were detected. A single 140-mg dose of evolocumab manufactured at the new site and administered in healthy Chinese subjects was associated with typical antibody pharmacokinetics, rapid and reversible decreases in LDL-C, and no new safety events.

Single-Dose Comparative Pharmacokinetics of Two Formulations of Lenalidomide 25mg in Healthy Subjects: A Randomized Crossover Study.

Lenalidomide is used for the treatment of multiple myeloma in combination with dexamethasone. The purpose of this study was to compare the pharmacokinetics (PKs) and assess the bioequivalence of two formulations of lenalidomide 25 mg: Lenalid® 25 mg tablet (test formulation) and Revlimid® 25 mg capsule (reference formulation). A randomized, single-dose, two-treatment, two-period, two-sequence crossover study was conducted in 42 healthy subjects. All subjects were randomly assigned to one of the two sequences, and they received a single dose of test or reference formulation in the first period and the alternative formulation during the next period under fasting conditions. Serial blood samples for PK evaluation were collected up to 24h post-dose and the PK parameters were estimated by non-compartmental methods. Throughout the study, tolerability was assessed on the basis of adverse events, vital signs, and clinical laboratory tests. The test formulation showed similar PK profiles to those of the reference formulation. The geometric mean ratio and 90% confidence interval (CI) of the test formulation to the reference formulation for maximum plasma concentration (Cmax) was 0.9995 (0.9250-1.0799) and the corresponding value for the area under the concentration-time curve from time zero to time of last quantifiable concentration (AUCt) was 0.9648 (0.9451-0.9850). Both CIs were within the conventional bioequivalence range of 0.8-1.25. The tolerability profile was not significantly different between the two formulations. This study found that the PKs of the two formulations of lenalidomide 25 mg were similar and the test formulation met the regulatory criteria for assuming bioequivalence with the reference formulation. Samyang Biopharmaceutical Corp.

MPEG-PLA/TPGS mixed micelles via intranasal administration improved the bioavailability of lamotrigine in the hippocampus.

PurposeThis study aimed to develop a novel methoxy poly(ethylene glycol)-poly(lactide) (mPEG-PLA)/D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) mixed micelle drug delivery system to improve lamotrigine (LTG) distribution in the hippocampus.MethodsLTG-loaded mPEG-PLA/TPGS mixed micelles and LTG-loaded mPEG-PLA micelles were formulated, and their characteristics, particle size, surface morphology, and release behavior in vitro were researched. Then, a microdialysis sampling technique coupled with two validated chromatographic systems was developed for the continuous measurement of the protein-unbound form of LTG in the rat plasma and hippocampus after administering two kinds of micelles and LTG solution intranasally.ResultsThe drug loading and mean size of LTG-loaded micelles and LTG-loaded mixed micelles prepared with optimal formulation were 36.44%±0.14%, 39.28%±0.26%, 122.9, and 183.5 nm, respectively, with a core–shell structure. The cumulative release rate in vivo of LTG-loaded mixed micelles was 84.21% at 24 hours and showed more sustained release while that of LTG-loaded micelles was 80.61% at 6 hours. The Tmax and area under concentration-time curve from zero to time of last quantifiable concentration of LTG solution, LTG-loaded micelles, and LTG-loaded mixed micelles were 55, 35, and 15 minutes and about 5,384, 16,500, and 25,245 (min⋅μg)/L in the hippocampus, respectively.ConclusionThe results revealed that LTG-loaded mPEG-PLA/TPGS mixed micelles enhanced the absorption of LTG at the nasal cavity and reduced the efflux of LTG in the brain, suggesting that the function of TPGS inhibited P-glycoprotein and LTG-loaded mPEG-PLA/TPGS mixed micelles had the potential to overcome refractory epilepsy.

Nicotine pharmacokinetic profiles of the Tobacco Heating System 2.2, cigarettes and nicotine gum in Japanese smokers

Two open-label randomized cross-over studies in Japanese smokers investigated the single-use nicotine pharmacokinetic profile of the Tobacco Heating System (THS) 2.2, cigarettes (CC) and nicotine replacement therapy (Gum).In each study, one on the regular and one on the menthol variants of the THS and CC, both using Gum as reference, 62 subjects were randomized to four sequences: Sequence 1: THS - CC (n = 22); Sequence 2: CC – THS (n = 22); Sequence 3: THS – Gum (n = 9); Sequence 4: Gum – THS (n = 9). Plasma nicotine concentrations were measured in 16 blood samples collected over 24 h after single use.Maximal nicotine concentration (Cmax) and area under the curve from start of product use to time of last quantifiable concentration (AUC0-last) were similar between THS and CC in both studies, with ratios varying from 88 to 104% for Cmax and from 96 to 98% for AUC0-last. Urge-to-smoke total scores were comparable between THS and CC.The THS nicotine pharmacokinetic profile was close to CC, with similar levels of urge-to-smoke. This suggests that THS can satisfy smokers and be a viable alternative to cigarettes for adult smokers who want to continue using tobacco.

Simultaneous Determination and Comparative Pharmacokinetics of Fuzi Water-Soluble Alkaloids between Normal and Acute Heart Failure Rats by Ultra Performance Liquid Chromatography Method.

In order to compare the pharmacokinetics of Fuzi water-soluble alkaloids between normal and acute heart failure rats, an ultra performance liquid chromatography (UPLC) method for simultaneous determination of it in rat plasma was developed. Plasma samples were treated by protein precipitation method. Seven water-soluble alkaloids were separated on a CAPCELL column and detected under the optimized chromatography condition. The calibration curves of seven targeted components showed good linearity with r2 > 0.9990 with average recoveries from 82.72 to 103.33% and matrix effect ranged from 90.02 to 104.03%. The intra- and inter-batch relative standard deviations were <10.72%, and the relative error of accuracy was within the range of -12.79-4.44%, respectively. After oral administration, the pharmacokinetic characteristics of it were investigated. Compared with the normal group, the Cmax and AUClast (area under the plasma concentration-time curve from the time of dosing to the time of last quantifiable concentration) of seven components except 3-Methoxy-p-tyramine Hydrochloride were obviously increased with remarkable prolonged t1/2 in acute heart failure group. In conclusion, a rapid, simple and sensitive UPLC method for the simultaneous quantification of seven water-soluble alkaloids in rat plasma was developed and validated for the first time. And the study showed that the disease condition had an impact on pharmacokinetics of Fuzi water-soluble alkaloids in rats in vivo.

Pharmacokinetics of intra-articular betamethasone sodium phosphate and betamethasone acetate and endogenous hydrocortisone suppression in exercising horses.

To the date, no reports exist of the pharmacokinetics (PK) of betamethasone (BTM) sodium phosphate and betamethasone acetate administered intra-articular (IA) into multiple joints in exercising horses. The purpose of the study was to determine the PK of BTM and HYD concentrations in plasma and urine after IA administration of a total of 30 mg BTM. Eight 4 years old Thoroughbred mares were exercised on a treadmill and BTM was administered IA. Plasma and urine BTM and HYD were determined via high performance liquid chromatography spectrometry for 6 weeks. Concentration-time profiles of BTM and HYD in plasma and urine were used to generate PK estimates for non-compartmental analyses and comparisons among times and HYD concentrations. BTM in plasma had greater Tmax (Tmax 0.8 h) vs. urine (Tmax 7.1 h). Urine BTM concentration (ng/mL) and amount (AUClast ; h × ng/mL) were greater than plasma. HYD was suppressed for at least 3 days (<1 ng/mL) for all horses. The time of last quantifiable concentration of BTM (Tlast ; hour) was not significantly different in plasma than urine. Use of highly sensitive HPLC-MS/MS assays enabled early detection and prolonged and consistent determination of BTM in plasma and urine.

Impact of ABCG2 and SLCO1B1 polymorphisms on pharmacokinetics of rosuvastatin, atorvastatin and simvastatin acid in Caucasian and Asian subjects: a class effect?

Systemic exposure to rosuvastatin is approximately double that of Caucasians in Asian subjects. We investigated whether this pattern of increased exposure exists for other statins. Plasma exposure following single-dose rosuvastatin 20 mg, atorvastatin 40 mg or simvastatin 40 mg was studied in Chinese, Japanese and Caucasian subjects. Plasma concentrations were determined using LC-MS methods. Impact of polymorphisms in SLCO1B1 (T521>C and A388>G) and in ABCG2 (C421>A) on exposure to rosuvastatin, atorvastatin, simvastatin and simvastatin acid was assessed. Relative to Caucasians, geometric mean area under the curve from time zero to time of last quantifiable concentration was 86 % (90 % confidence interval (CI), 51-130 %) and 55 % (26-91 %) higher for rosuvastatin in Chinese and Japanese subjects, respectively, 53 % (25-88 %) and 69 % (37-108 %) higher for atorvastatin, 23 % (0-52 %) and 12 % (-0.9-39 %) higher for simvastatin and 28 % (5-56 %) and 34 % (10-64 %) higher for simvastatin acid. Geometric mean maximum drug concentration was also proportionally higher for each statin. Polymorphisms in SLCO1B1 T521>C or ABCG2 C421>A were associated with higher exposure to rosuvastatin, atorvastatin and simvastatin acid (but not simvastatin) within a population, but only the ABCG2 C421>A polymorphism contributed towards between-population exposure differences. In individuals carrying wild-type alleles for both SLCO1B1 and ABCG2, area under the plasma concentration-time curve (AUC) still appeared to be higher for rosuvastatin, atorvastatin and simvastatin acid in Chinese and Japanese subjects compared with Caucasians, respectively. Increased exposure to statins in Asian subjects versus Caucasians may represent a more general class phenomenon than previously recognized.

Safety, tolerability, and pharmacokinetics of a single ascending dose of baicalein chewable tablets in healthy subjects

Ethnopharmacological relevanceThe root of Scutellaria baicalensis Georgi has been used extensively in traditional Chinese medicine for the treatment of inflammation, fever, cough, dysentery, and hypertension. Baicalein is a flavonoid isolated from the root of Scutellaria baicalensis Georgi and is a novel neuroprotective agent under development for the treatment of Parkinson׳s disease. We aimed to investigate the pharmacokinetic (PK) properties of baicalein and its main metabolite, bacalin, after single-dose administration in healthy Chinese subjects. The safety and tolerability of baicalein were also assessed. Materials and methodsThis was a Phase I, randomized, double-blind, single-dose trial of baicalein (100–2800mg) in 72 healthy adults. Samples of blood, urine and feces were collected at regular intervals up to 48h after administration of the study drug. Baicalein and baicalin were then analyzed using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The maximum concentration that the drug achieved after dosing (Cmax), time to Cmax (Tmax), terminal half-life (t1/2), area under the curve from time zero to time of last quantifiable concentration (AUC(0, t)), area under the curve from time zero to infinity (AUC(0, ∞)), apparent total plasma clearance (CL/F), and apparent total volume of distribution (V/F) were determined using non-compartmental models. Dose proportion was tested using a method combining the equivalence criterion and power model. Physical examinations, vital signs, ECG findings, hematology, and urinalysis were monitored before and at regular intervals after administration of the study drug. ResultsThe PK profile of baicelein and baicelin was characterized by a median Tmax of 0.75–3.5h and 0.5–3h, respectively, followed by a multiphasic profile with a t1/2 of 1.90–15.01h and 4.22–10.80h, respectively. The estimates of the proportionality coefficient (90% CI) for Cmax, AUC0–t and AUC0–∞ were 0.83 (0.70–0.96), 0.91 (0.81–1.00) and 0.92 (0.82–1.02), respectively. All values overlapped within the pre-specified range of (0.89–1.11), (0.93–1.07), and (0.93–1.07), respectively. Dose proportionality was inconclusive for a baicalein dose range of 100–2800mg. The total urinary clearance of baicalein and baicalin was <1%. Approximately 27% of baicalein was eliminated as unchanged drug in feces. Baicalein was well tolerated. Eleven treatment-related adverse events were observed, and all were rated as “mild” and resolved without further treatment. No serious adverse events occurred. ConclusionsSingle oral doses of 100–2800mg of baicalein were safe and well tolerated by healthy subjects. Clinical laboratory assessments showed no signs of toxicity in the liver or kidney. The favorable safety profile and PK properties warrant further clinical studies for baicalein.