Comparison of lumefantrine, mefloquine, and piperaquine concentrations between capillary plasma and venous plasma samples in pregnant women with uncomplicated falciparum and vivax malaria.

Capillary samples offer practical benefits compared with venous samples for the measurement of drug concentrations, but the relationship between the two measures varies between different drugs. We measured the concentrations of lumefantrine, mefloquine, piperaquine in 270 pairs of venous plasma and concurrent capillary plasma samples collected from 270 pregnant women with uncomplicated falciparum or vivax malaria. The median and range of venous plasma concentrations included in this study were 447.5 ng/mL (8.81-3,370) for lumefantrine (day 7, n = 76, median total dose received 96.0 mg/kg), 17.9 ng/mL (1.72-181) for desbutyl-lumefantrine, 1,885 ng/mL (762-4,830) for mefloquine (days 3-21, n = 90, median total dose 24.9 mg/kg), 641 ng/mL (79.9-1,950) for carboxy-mefloquine, and 51.8 ng/mL (3.57-851) for piperaquine (days 3-21, n = 89, median total dose 52.2 mg/kg). Although venous and capillary plasma concentrations showed a high correlation (Pearson's correlation coefficient: 0.90-0.99) for all antimalarials and their primary metabolites, they were not directly interchangeable. Using the concurrent capillary plasma concentrations and other variables, the proportions of venous plasma samples predicted within a ±10% precision range was 34% (26/76) for lumefantrine, 36% (32/89) for desbutyl-lumefantrine, 74% (67/90) for mefloquine, 82% (74/90) for carboxy-mefloquine, and 24% (21/89) for piperaquine. Venous plasma concentrations of mefloquine, but not lumefantrine and piperaquine, could be predicted by capillary plasma samples with an acceptable level of agreement. Capillary plasma samples can be utilized for pharmacokinetic and clinical studies, but caution surrounding cut-off values is required at the individual level.CLINICAL TRIALSThis study is registered with ClinicalTrials.gov as NCT01054248.

Heart Failure and PAHs, OHPAHs, and Trace Elements Levels in Human Serum: Results from a Preliminary Pilot Study in Greek Population and the Possible Impact of Air Pollution.

Cardiovascular diseases (CVDs) have been associated with environmental pollutants. The scope of this study is to assess any potential relation of polycyclic aromatic hydrocarbons (PAHs), their hydroxylated derivatives, and trace elements with heart failure via their direct determination in human serum of Greek citizens residing in different areas. Therefore, we analyzed 131 samples including cases (heart failure patients) and controls (healthy donors), and the respective demographic data were collected. Significantly higher concentrations (p < 0.05) were observed in cases' serum regarding most of the examined PAHs and their derivatives with phenanthrene, fluorene, and fluoranthene being the most abundant (median of >50 µg L-1). Among the examined trace elements, As, Cd, Cu, Hg, Ni, and Pb were measured at statistically higher concentrations (p < 0.05) in cases' samples, with only Cr being significantly higher in controls. The potential impact of environmental factors such as smoking and area of residence has been evaluated. Specific PAHs and trace elements could be possibly related with heart failure development. Atmospheric degradation and smoking habit appeared to have a significant impact on the analytes' serum concentrations. PCA-logistic regression analysis could possibly reveal common mechanisms among the analytes enhancing the hypothesis that they may pose a significant risk for CVD development.

Pharmacokinetics, Safety, and Tolerability of Ledipasvir/Sofosbuvir and Sofosbuvir/Velpatasvir in Healthy Chinese Subjects.

PURPOSE: Ledipasvir/sofosbuvir and sofosbuvir/velpatasvir have been approved worldwide for the treatment of chronic hepatitis C virus (HCV) infection. Although both have been approved in China, there are currently no data on their pharmacokinetic profiles in Chinese individuals. Two studies investigated the pharmacokinetic properties, safety, and tolerability of ledipasvir/sofosbuvir and sofosbuvir/velpatasvir, respectively, in healthy Chinese subjects. METHODS: Two Phase I, open-label, single- and multiple-dose studies were conducted in healthy Chinese subjects. Ledipasvir/sofosbuvir (90/400 mg) or sofosbuvir/velpatasvir (400/100 mg), respectively, was administered orally once daily under fasted conditions. Subjects received a single dose (day 1) and multiple doses (days 8-17 [ledipasvir/sofosbuvir]; days 8-14 [sofosbuvir/velpatasvir]). Plasma pharmacokinetic parameters were estimated by using noncompartmental models, and safety was assessed through clinical evaluation and monitoring of adverse events. FINDINGS: Fourteen subjects were enrolled in each study (7 men, 7 women each; mean age, 30 years [ledipasvir/sofosbuvir] and 29 years [sofosbuvir/velpatasvir]). The pharmacokinetic parameters for sofosbuvir, GS-566500, GS-331007, and ledipasvir or velpatasvir were similar to historical values in non-Chinese subjects. Consistent with the t1/2 of ledipasvir relative to 24-h dosing, accumulation of 177% (AUC) and 107% (Cmax) was observed. There was no significant accumulation of velpatasvir, sofosbuvir, GS-566500, or GS-331007. Both drugs were generally well tolerated; no serious adverse events or discontinuations due to adverse events were reported. IMPLICATIONS: Overall, ledipasvir/sofosbuvir and sofosbuvir/velpatasvir exhibited pharmacokinetic and safety profiles in healthy Chinese subjects similar to those in non-Chinese subjects in historical studies, supporting their use in the Chinese population with HCV infection. ChinaDrugTrials.org.cn identifiers: CTR20160149 (ledipasvir/sofosbuvir); CTR20160602 (sofosbuvir/velpatasvir).

CYP2B6*6 Genotype Specific Differences in Artemether-Lumefantrine Disposition in Healthy Volunteers.

Cytochrome P450 2B6 (CYP2B6) is involved in the metabolism of the antimalarial drugs artemether and lumefantrine. Here we investigated the effect of CYP2B6*6 on the plasma pharmacokinetics of artemether, lumefantrine, and their metabolites in healthy volunteers. Thirty healthy and previously genotyped adult volunteers-15 noncarriers (CYP2B6*1/*1) and 15 homozygote carriers (CYP2B6*6/*6)-selected from a cohort of 150 subjects from the Ilorin metropolitan area were administered the complete 3-day course of artemether and lumefantrine (80 and 480 mg twice daily, respectively). Intensive pharmacokinetic sampling was conducted at different time points before and after the last dose. Plasma concentrations of artemether, lumefantrine, dihydroartemisinin, and desbutyllumefantrine were quantified using validated liquid chromatography-mass spectrometric methods. Pharmacokinetic parameters were evaluated using noncompartmental analysis. Artemether clearance of CYP2B6*6/*6 volunteers was nonsignificantly lower by 26% (ratios of geometric mean [90% CI]; 0.74 [0.52-1.05]), and total exposure (the area under the plasma concentration-time curve from time 0 to infinity [AUC0-∞ ]) was greater by 35% (1.35 [0.95-1.93]) when compared with those of *1/*1 volunteers. Similarly, assuming complete bioconversion from artemether, the dihydroartemisinin AUC0-∞ was 22% lower. On the contrary, artemether-to-dihydroartemisinin AUC0-∞ ratio was 73% significantly higher (1.73 [1.27-2.37]). Comparison of lumefantrine exposure and lumefantrine-to-desbutyllumefantrine metabolic ratio of *6/*6 with corresponding data from *1/*1 volunteers showed no differences. The increased artemether-to-dihydroartemisinin metabolic ratio of *6/*6 volunteers is unlikely to result in differences in artemether-lumefantrine efficacy and treatment outcomes. This is the first study in humans to associate CYP2B6*6 genotype with artemether disposition.

Estimating Efflux Transporter-Mediated Disposition of Molecules beyond the Rule of Five (bRo5) Using Transporter Gene Knockout Rats.

Transporter gene knockout models are a practical and widely used tool for pharmacokinetic studies in drug discovery. P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) are major efflux transporters that control absorption and bioavailability, and are important when determining oral drug disposition. To the best of our knowledge, beyond the rule of five (bRo5) molecules launched on the market to date tend to be substrates for efflux transporters. The purpose of this study is to evaluate in vivo the impact of efflux transporters on the oral absorption process and systemic clearance using rats which lack P-gp and/or Bcrp expression. We administered five bRo5 substrates (asunaprevir, cyclosporine, danoprevir, ledipasvir, and simeprevir) intravenously or orally to wild-type and Mdr1a, Bcrp, and Mdr1a/Bcrp knockout rats, calculated the clearance, oral bioavailability, and absorption rate profile of each substrate, and compared the results. Systemic clearance of the substrates in knockout rats changed within approximately ±40% compared to wild-types, suggesting the efflux transporters do not have a significant influence on clearance in rats. On the other hand, the oral absorption of substrates in the knockout rats, especially those lacking Mdr1a, increased greatly-between 2- and 5-fold more than in wild-types. This suggests that rat efflux transporters, especially P-gp, greatly reduce the oral exposure of these substrates. Moreover, results on the absorption rate-time profile suggest that efflux transporters are constantly active during the absorption period in rats. Transporter knockout rats are a useful in vivo tool for estimating the transporter-mediated disposition of bRo5 molecules in drug discovery.

Micellar-based spectrofluorimetric method for the selective determination of ledipasvir in the presence of sofosbuvir: application to dosage forms and human plasma.

A fast, low-cost, sensitive, and selective spectrofluorimetric method for the determination of ledipasvir was developed and validated. The method is based on an enhancement in the native fluorescence intensity of ledipasvir by 500% of its original value by the formation of hydrogen bonds between the cited drug and Tween-20 in the micellar system (pH = 5.0). All fluorescence measurements were carried out at 425 nm and 340 nm for emission and excitation wavelengths, respectively. A linear relationship between the concentration of ledipasvir and the observed fluorescence intensity was achieved in the range of 0.1-2.0 µg ml-1 with 0.028, 0.084 µg ml-1 , for detection and quantitation limits, respectively. The acquired selectivity and sensitivity using the proposed method facilitate the analysis of ledipasvir in spiked human plasma with sufficient percentage recovery (95.36-99.30%). The proposed method was developed and validated according to International Council for Harmonisation (ICH) guidelines. Moreover, the cited drug was successfully determined in its pharmaceutical dosage form using the proposed method. In addition, the validity of the proposed results was statistically confirmed using Student's t-test, variance ratio F-test, and interval hypothesis test.

Pharmacokinetic evaluation of daclatasvir and ledipasvir in healthy volunteers using a validated highly sensitive spectrofluorimetric method.

A simple, highly sensitive and selective spectrofluorimetric method has been developed and fully validated for the determination of daclatasvir (DAC) and ledipasvir (LED) in tablets and human plasma. The method is based on measurement of the native fluorescence in methanol at λem 384 nm after excitation at λex 318 nm for DAC and in acetonitrile at λem 402 nm after excitation at λex 340 nm for LED. The fluorescence intensity (FI) concentration plot was rectilinear over the ranges 1.2-12, 0.1-18 ng ml-1 and 9-90, 1-100 ng ml-1 with a good correlation of r = 0.9994 to r = 0.9997 in standard solution and human plasma for DAC and LED, respectively. The extraction of analytes from plasma was performed using methanol and acetonitrile as a precipitating agent with lower limit of quantification (LLOQ) of 0.1 and 1.0 ng ml-1 for DAC and LED; respectively. The proposed method was validated according to the US Food and Drug Administration (FDA) guidelines and successfully applied for estimating the pharmacokinetic parameters of DAC and LED following oral administrations of their tablets.

New, simple and sensitive HPTLC method for simultaneous determination of anti-hepatitis C sofosbuvir and ledipasvir in rabbit plasma.

Sofosbuvir (SOF) and ledipasvir (LDS) represent anti-hepatitis C binary mixture. Herein, a fast high-performance thin-layer chromatography (HPTLC) method was developed, validated and applied for simultaneous determination of SOF and LDS in biological matrix. An innovative strategy was designed which based on coupling dual wavelength detection with HPTLC. This strategy enabled sensitive, specific, high sample throughput and cost-effective determination of the SOF-LDS binary mixture. The developed HPTLC procedure is based on a simple liquid-liquid extraction, enrichment of the analytes and subsequent separation with UV detection. Separations were performed on HPTLC silica gel 60 F254 aluminum plates with a mobile phase consisting of ethyl acetate-glacial acetic acid (100:5, v/v). The Rf values for SOF and LDS were 0.62 and 0.30, respectively. Dual wavelength scanning was carried out in the absorbance mode at 265 and 327 nm for SOF and LDS, respectively. The linear ranges were 40-640 and 9-144 ng/band for SOF and LDS, respectively with correlation coefficients of 0.9998. The detection limits were 10.61 and 2.54 ng/band and the quantitation limits were 32.14 and 7.70 ng/band for SOF and LDS, respectively indicating high sensitivity of the proposed method. Consequently, this permits in vitro and in vivo application of the proposed method in rabbit plasma with good percentage recovery (95.68-103.26%). Validation parameters were assessed according to ICH guidelines. The proposed method represents a simple, high sample throughput and economic alternative to the already existing more complicated reported LC-MS/MS techniques. The method would afford an efficient tool for therapeutic drug monitoring and bioavailability studies of SOF and LDS.

Specific stability indicating spectrofluorimetric method for determination of ledipasvir in the presence of its confirmed degradation products; application in human plasma.

A rapid and specific spectrofluorimetric method with higher sensitivity was developed for determination of ledipasvir (LDS) in tablets and human plasma. The proposed method relies on hydrogen bonding formations between the hydroxyl groups of polyoxyethylene 50 stearate and LDS, causing significant enhancement of its native fluorescence. The fluorescence intensity was measured at 430 nm after excitation at 340 nm. The fluorescence-concentration plot was rectilinear over the range 1-400 ng mL-1 with detection and quantification limits of 0.25 and 1.10 ng mL-1, respectively. The high sensitivity of the proposed method permits its application for ledipasvir determinations in real human plasma even in the presence of co-administered drugs sofosbuvir and ribavirin. Moreover, the proposed method was further extended to stability studies of ledipasvir after exposure to different forced degradation conditions according to ICH guidelines, along with the structural elucidation of its degradation products utilizing IR and Mass spectra. A proposal for the degradation pathways was presented.

Molecularly imprinted polymer for determination of lumefantrine in human plasma through chemometric-assisted solid-phase extraction and liquid chromatography.

Lumefantrine is the first-choice treatment of Falciparum uncomplicated malaria. Recent findings of resistance to lumefantrine has brought attention for the importance of therapeutic monitoring, since exposure to subtherapeutic doses of antimalarials after administration is a major cause of selection of resistant parasites. Therefore, this study focused on the development of innovative, selective, less expensive and stable molecularly imprinted polymers (MIPs) for solid-phase extraction (SPE) of lumefantrine from human plasma to be used in drug monitoring. Polymers were synthesized by precipitation polymerization and chemometric tools (Box-Behnken design and surface response methodology) were employed for rational optimization of synthetic parameters. Optimum conditions were achieved with 2-vinylpyridine as monomer, ethylene glycol dimethacrylate as crosslinker and toluene as porogen, at molar ratio of 1:6:30 of template/monomer/crosslinker and azo-bisisobutyronitrile as initiator at 65 °C. The MIP obtained was characterized and exhibited high thermal stability, adequate surface morphology and porosity characteristics and high binding properties, with high affinity (adsorption capacity of 977.83 µg g-1) and selectivity (imprinting factor of 2.44; and selectivity factor of 1.48 and selectivity constant of 1.44 compared with halofantrine). Doehlert matrix and fractional designs were satisfactorily used for development and optimization of a MISPE-HPLC-UV method for determination of lumefantrine. The method fulfilled all validation parameters, with recoveries ranging from 83.68% to 85.42%, and was applied for quantitation of the drug in plasma from two healthy volunteers, with results of 1407.89 and 1271.35 ng mL-1, respectively. Therefore, the MISPE-HPLC-UV method optimized through chemometrics provided a rapid, highly selective, less expensive and reproducible approach for lumefantrine drug monitoring.

A sensitive, high-throughput, and ecofriendly method for the determination of lumefantrine, artemether, and its active metabolite dihydroartemisinin by supercritical fluid chromatography and tandem mass spectrometry.

A quick and sensitive supercritical fluid chromatography with tandem mass spectrometry method for the simultaneous determination of lumefantrine, artemether, and its active metabolite dihydroartemisinin in rat plasma was developed and validated. The chromatographic separation was performed on an ACQUITY UPC2 ™ BEH 2-EP column within 2.5 min by gradient elution using compressed CO2 and methanol containing 2 mM ammonium acetate as the mobile phases. Detection was achieved by multiple reaction monitoring using electrospray ionization in the positive ionization mode. For sample preparation, 50 µL of the sample was processed by modified high-throughput, one-step protein precipitation using hydrogen peroxide as a stabilizer to protect the endoperoxide-containing artemisinin derivatives from degradation. The calibration curves were linear over the concentration range of 2.0-1000 ng/mL for both artemether and dihydroartemisinin, and 1.0-5000 ng/mL for lumefantrine. The values of selectivity, lower limit of quantification, linearity, accuracy, precision, matrix effects, stability, and recovery met the acceptable range according to the Food and Drug Administration guidelines. The developed method enables high resolution and speed as well as low cost, low solvent consumption, and short time and was successfully applied to pharmacokinetic studies through the intravenous administration of an artemether-lumefantrine lipid emulsion in rats.

Semi-quantitative measurement of the antimalarial lumefantrine from untreated dried blood spots using LC-MS/MS.

Study of the clinical effects of combination therapy for malaria is aided by the ability to measure concentrations of individual partner drugs. Existing methods for measurement of the antimalarial drug lumefantrine (LF) in dried blood spots (DBS) on filter paper rely on chemical pretreatment of the paper to facilitate drug elution. However, in the absence of pretreatment, DBS may still offer some utility for semi-quantitative measurements and pharmacokinetic-pharmacodynamic (PK-PD) analyses. We present a method for semi-quantitation of LF in DBS on untreated filter paper using liquid chromatography tandem mass spectrometry. Optimal recovery was achieved by extraction with acetone-water-formic acid (90:5:5). The range of quantitation was 100-20,000ng/ml. Mean intra- and inter-day accuracy values were 86.6% (coefficient of variation [CV]: 10.1%) and 91.8% (CV: 16.1%), therefore we propose the assay as semi-quantitative. Clinical application was demonstrated in exploratory PK-PD analyses of a drug efficacy trial of artemether-lumefantrine in children with uncomplicated falciparum malaria using post-treatment day 7 samples, parasite clearance times estimated from serial blood smears, and recurrence of malaria out to 35days. The median day 7 concentration among children (n=71) was 111ng/ml (interquartile range: 100-194ng/ml). We used a truncated calibration curve of 100-5000ng/ml for calculations due to low observed concentrations. Calculations using the full calibration curve yielded similar values (+1% avg. deviation). Controlling for participant age, sex, and parasite burden, each log increase in LF day 7 concentration corresponded to a decrease of 7.1h in mean parasite clearance time (95% confidence interval: 0.1-14.3h, P=0.05). A nested case-control study of participants (n=18) with and without recurrent malaria showed mean post-treatment day 7 concentrations of 181ng/ml and 235ng/ml, respectively, but the difference was not significant (P=0.64). A method for semi-quantitation of LF from post-treatment day 7 collections of DBS on untreated filter paper demonstrated clinical application in exploratory PK-PD analyses of parasite clearance and reinfection. Use of DBS will endure in certain study settings by virtue of their ease of collection and resilience. Their utility should continue to be explored as our instruments gain in sensitivity and as clinical pharmacology inquiries are pursued to the field.

LC-MS/MS method for the simultaneous analysis of seven antimalarials and two active metabolites in dried blood spots for applications in field trials: Analytical and clinical validation.

In epidemiological studies, antimalarials measurements in blood represent the best available marker of drugs exposure at population level, an important driver for the emergence of drug resistance. We have developed a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for the simultaneous quantification of 7 frequently used antimalarials (amodiaquine, chloroquine, quinine, sulfadoxine, pyrimethamine, mefloquine, lumefantrine) and 2 active metabolites (N-desethyl-amodiaquine, desbutyl-lumefantrine) in 10-µl dried blood spots (DBS). This sampling approach is suitable for field studies wherein blood samples processing, transportation and storage are problematic. Sample preparation included extraction from a 3 mm-disk punched out of the DBS with 100-µl of methanol + 1% formic acid containing deuterated internal standards for all drugs. Good performances were achieved in terms of trueness (-12.1 to +11.1%), precision (1.4-15.0%) and sensitivity, with lower limits of quantification comprised between 2 ng/ml (sulfadoxine) and 20 ng/ml (chloroquine, quinine, pyrimethamine, mefloquine, lumefantrine and desbutyl-lumefantrine). All analytes were stable in DBS kept for 24 h at room temperature and at 37 °C. The developed assay was applied within the frame of a pharmacokinetic study including 16 healthy volunteers who received a single dose of artemether-lumefantrine. Lumefantrine concentrations in plasma and in DBS were highly correlated (R = 0.97) at all time points, confirming the assumption that lumefantrine concentrations determined in DBS confidently reflect blood concentrations. The blood/plasma ratio of 0.56 obtained using the Bland-Altman approach (and corresponding to the slope of the linear regression) is in line with very low penetration of lumefantrine into red blood cells. This sensitive multiplex LC-MS/MS assay enabling the simultaneous analysis of antimalarials in DBS is suitable for epidemiological studies in field conditions.

A facile synthesis of 3D NiFe2O4 nanospheres anchored on a novel ionic liquid modified reduced graphene oxide for electrochemical sensing of ledipasvir: Application to human pharmacokinetic study.

Novel and sensitive electrochemical sensor was fabricated for the assay of anti-HCV ledipasvir (LEDV) in different matrices. The designed sensor was based on 3D spinel ferromagnetic NiFe2O4 nanospheres and reduced graphene oxide (RGO) supported by morpholinium acid sulphate (MHS), as an ionic liquid (RGO/NSNiFe2O4/MHS). This sensor design was assigned to synergistically tailor the unique properties of nanostructured ferrites, RGO, and ionic liquid to maximize the sensor response. Electrode modification prevented aggregation of NiFe2O4, increasing electroactive surface area and allowed remarkable electro-catalytic oxidation of LEDV with an enhanced oxidation response. Differential pulse voltammetry was used for detection LEDV in complex matrices whereas; cyclic voltammetry and other techniques were employed to characterize the developed sensor properties. All experimental factors regarding sensor fabrication and chemical sensing properties were carefully studied and optimized. Under the optimum conditions, the designated sensor displayed a wide linear range (0.4-350 ng mL-1) with LOD of 0.133 ng mL-1. Additionally, the proposed sensor demonstrated good selectivity, stability and reproducibility, enabling the quantitative detection of LEDV in Harvoni® tablets, human plasma and in a pharmacokinetic study. Our findings suggest that the developed sensor is a potential prototype material for fabrication of high-performance electrochemical sensors.

Ultrasensitive spectrofluorimetric method for rapid determination of daclatasvir and ledipasvir in human plasma and pharmaceutical formulations.

Direct-acting antivirals (DAAs) represent a revolution in the treatment of chronic hepatitis C which have emerged at an extremely rapid pace over the past few years. DAAs act directly on the hepatitis C virus at various points in the viral life cycle to inhibit viral production. Among these novel DAAs, are daclatasvir (DCS) and ledipasvir (LDS). Herein, a novel, fast, simple, ultrasensitive and cost-effective spectrofluorimetric method was designed for determination of DCS and LDS in miscellaneous matrices. The method is based on investigation of the native fluorescence of the cited drugs. The relative fluorescence intensity (RFI) was measured at λex/λem equal to 315/381 nm for DCS and 332/387 nm for LDS. Under the optimum conditions, the linear ranges of calibration curves were 0.2-30 and 6-120 ng mL-1 for DCS and LDS, respectively with correlation coefficients ≥0.9998. The detection limits were 0.047 and 1.939 ng mL-1 for DCS and LDS, respectively indicating ultrasensitivity of the proposed method. Consequently, this permits in vitro and in vivo application of the proposed method in spiked and real human plasma with good percentage recovery (96.6-103.6%). The method was validated in compliance with ICH guidelines and US-FDA guidelines. Furthermore, the application was extended to analysis of DCS and LDS in its pharmaceutical formulations (either alone or in presence of other co-formulated drugs) and in synthetic mixture with sofosbuvir or ribavirin.

A Thorough QT Study to Evaluate the Effects of Supratherapeutic Doses of Ledipasvir on the QTc Interval in Healthy Subjects.

This study evaluated the effect of supratherapeutic exposure of the anti-HCV drug ledipasvir on the QTc interval in healthy subjects. Sixty healthy volunteers were randomized to receive twice-daily blinded ledipasvir (120 mg) or placebo, administered for 10 days each, or single doses of open-label moxifloxacin (400 mg). Serial plasma samples for ledipasvir concentration analysis were collected after each treatment. Triplicate time-matched electrocardiograms were collected at baseline and after each treatment. Change from baseline in the QTc for ledipasvir or moxifloxacin versus placebo was determined using several correction formulas (primary: QTcF [Fridericia's]; secondary: QTcN [population] and QTcI [individual]). Pharmacokinetics and exposure-QTc relationships were evaluated. Ledipasvir AUC0-24 and Cmax achieved approximately 3.7-fold and 4.2-fold, respectively, above exposures observed following administration of ledipasvir/sofosbuvir (90/400 mg) to HCV-infected patients. There was a lack of effect of supratherapeutic ledipasvir on QTc intervals using all correction methods (upper bound of the 2-sided 90%CIs for the mean difference in time-matched baseline-corrected QTc between ledipasvir versus placebo < 10 milliseconds at all times). The lower bound of the 2-sided 96.67%CI for the mean difference in moxifloxacin versus placebo was >5 milliseconds, thereby establishing assay sensitivity. Categorical analyses did not demonstrate clinically relevant effects of ledipasvir on QTc intervals or other electrocardiogram parameters. No relationships between ledipasvir plasma concentration and QTc interval were observed. Ledipasvir does not prolong QTc interval. Based on these results and a previous TQT evaluation for sofosbuvir, the fixed-dose combination regimen of ledipasvir/sofosbuvir is not expected to prolong the QTc interval.

Liquid chromatography coupled with hybrid ion trap time-of-flight mass spectrometry method for the determination of caulophine in rat bio-samples and its pharmacokinetic study after intragastric and intraperitoneal administration.

A rapid and precise liquid chromatography coupled with hybrid ion trap/time-of-flight mass spectrometry method to detect and quantify caulophine and its possible active metabolites in rat plasma and urine was developed. Samples were prepared by plasma protein precipitation combined with a liquid-liquid extraction method. The separation was carried out on an InertSustain® C18 column with a mobile phase comprising methanol and 0.1% aqueous formic acid solution. The analysis was complete in 20 min with a flow rate of 0.4 mL/min. Taspine was used as the internal standard. Mass spectrometric detection was conducted with hybrid ion trap/time-of-flight equipped with electrospray ionization in the positive ion mode. The calibration curves of caulophine were linear over the concentration ranges of 0.002-0.20 µg/mL for plasma and 0.005-0.50 µg/mL for urine with the correlation coefficients greater than 0.998 in both cases. The method was successfully used to investigate the pharmacokinetics and bioavailability in rat plasma and urine samples after intragastric and intraperitoneal administration of caulophine sodium salt.

Ledipasvir and tenofovir drug interaction in human immunodeficiency virus-hepatitis C virus coinfected patients: Impact on tenofovir trough concentrations and renal safety.

We evaluate the impact of ledipasvir on both tenofovir plasma trough concentration and estimated glomerular renal function in human immunodeficiency virus-hepatitis C virus coinfected patients receiving a tenofovir-based antiretroviral regimen and treated with ledipasvir/sofosbuvir. Twenty-six patients [81% male, median age: 51 years; hepatitis C virus genotype 1(75%)/4(15%)] were included. Tenofovir trough concentration (interquartile range) increased from 78 ng ml-1 (53-110) at baseline to 141 ng ml-1 (72-176) at 1 month (P = 0.003). No significant difference on estimated glomerular renal function using both Cockroft-Gault and Modification of Diet in Renal Disease formulae, respectively, [median (interquartile range)] was observed between baseline [101.3 ml min-1 (91.1-114.1); 95.6 ml min-1 (86.5-111.2)], 1 month [102.4 ml min-1 (89.8-112.9), P = 0.26; 92.5 ml min-1 (88.1-114.3), P = 0.27], end-of-treatment [96.5 ml min-1 (82.4-115.4), P = 0.39; 95.4 ml min-1 (84.2-105.4), P = 0.16] and 12 weeks after the end of treatment [100.5 ml min-1 (83.3-111.9), P = 0.24; 93.4 ml min-1 (82.2-103.5), P = 0.16]. Three patients progressed from chronic kidney disease stage 1 to stage 2 at 12 weeks post-treatment. A significant increase in tenofovir exposure through P-glycoprotein inhibition by ledipasvir was confirmed without significant impact on glomerular renal function in our population with normal renal function or mild renal impairment.

Assessment of Efficacy and Safety of Arterolane Maleate-Piperaquine Phosphate Dispersible Tablets in Comparison With Artemether-Lumefantrine Dispersible Tablets in Pediatric Patients With Acute Uncomplicated Plasmodium falciparum Malaria: A Phase 3, Randomized, Multicenter Trial in India and Africa.

BACKGROUND: Administration of artemisinin-based combination therapy (ACT) to infant and young children can be challenging. A formulation with accurate dose and ease of administration will improve adherence and compliance in children. The fixed-dose combination dispersible tablet of arterolane maleate (AM) 37.5 mg and piperaquine phosphate (PQP) 187.5 mg can make dosing convenient in children. METHODS: This multicenter (India and Africa), comparative, parallel-group trial enrolled 859 patients aged 6 months to 12 years with Plasmodium falciparum malaria. Patients were randomized in a ratio of 2:1 to AM-PQP (571 patients) once daily and artemether-lumefantrine (AL) (288 patients) twice daily for 3 days and followed for 42 days. RESULTS: The cure rate (ie, polymerase chain reaction-corrected adequate clinical and parasitological response) in the per-protocol population at day 28 was 100.0% and 98.5% (difference, 1.48% [95% confidence interval {CI}, .04%-2.91%]) in the AM-PQP and AL arms, respectively, and 96.0% and 95.8% (difference, 0.14% [95% CI, -2.68% to 2.95%]) in the intention-to-treat (ITT) population. The cure rate was comparable at day 42 in the ITT population (AM-PQP, 94.4% vs AL, 93.1%). The median parasite clearance time was 24 hours in both the arms. The median fever clearance time was 6 hours in AM-PQP and 12 hours in the AL arm. Both the treatments were found to be safe and well tolerated. Overall, safety profile of both the treatments was similar. CONCLUSIONS: The efficacy and safety of fixed-dose combination of AM and PQP was comparable to AL for the treatment of uncomplicated P. falciparum malaria in pediatric patients. CLINICAL TRIALS REGISTRATION: CTRI/2014/07/004764.

Effect of pharmacogenetics on plasma lumefantrine pharmacokinetics and malaria treatment outcome in pregnant women.

BACKGROUND: Pregnancy has considerable effects on the pharmacokinetic properties of drugs used to treat uncomplicated Plasmodium falciparum malaria. The role of pharmacogenetic variation on anti-malarial drug disposition and efficacy during pregnancy is not well investigated. The study aimed to examine the effect of pharmacogenetics on lumefantrine (LF) pharmacokinetics and treatment outcome in pregnant women. METHODS: Pregnant women with uncomplicated falciparum malaria were enrolled and treated with artemether-lumefantrine (ALu) at Mkuranga and Kisarawe district hospitals in Coast Region of Tanzania. Day-7 LF plasma concentration and genotyping forCYP2B6 (c.516G>T, c.983T>C), CYP3A4*1B, CYP3A5 (*3, *6, *7) and ABCB1 c.4036A4G were determined. Blood smear for parasite quantification by microscopy, and dried blood spot for parasite screening and genotyping using qPCR and nested PCR were collected at enrolment up to day 28 to differentiate between reinfection from recrudescence. Treatment response was recorded following the WHO protocol. RESULTS: In total, 92 pregnant women in their second and third trimester were included in the study and 424 samples were screened for presence of P. falciparum. Parasites were detected during the follow up period in 11 (12%) women between day 7 and 28 after treatment and PCR genotyping confirmed recrudescent infection in 7 (63.3%) women. The remaining four (36.4%) pregnant women had reinfection: one on day 14 and three on day 28. The overall PCR-corrected treatment failure rate was 9.0% (95% CI 4.4-17.4). Day 7 LF concentration was not significantly influenced by CYP2B6, CYP3A4*1B and ABCB1 c.4036A>G genotypes. Significant associations between CYP3A5 genotype and day 7 plasma LF concentrations was found, being higher in carriers of CYP3A5 defective variant alleles than CYP3A5*1/*1 genotype. No significant influence of CYP2B6, CYP3A5 and ABCB1 c.4036A>Genotypes on malaria treatment outcome were observed. However, CYP3A4*1B did affect malaria treatment outcome in pregnant women followed up for 28 days (P = 0.018). CONCLUSIONS: Genetic variations in CYP3A4 and CYP3A5may influence LF pharmacokinetics and treatment outcome in pregnant women.