scholarly journals The Statistical Analysis of Pharmacokinetic Parameters in the Context of Bioequivalence Testing of Two Anthelmintic Formulas Based on Ivermectine and Triclabendazole in Sheep

2019 ◽  
Vol 65 (2) ◽  
pp. 60-65
Author(s):  
Lenard Farczadi ◽  
Laurian Vlase ◽  
Orsolya Melles ◽  
Ramona Tolomeiu ◽  
Octavia Tamas-Krumpe ◽  
...  
Keyword(s):  
High Performance ◽  
Reference Product ◽  
Plasma Concentrations ◽  
Pharmaceutical Formulations ◽  
Relative Bioavailability ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Test Product

AbstractConducting bioequivalence studies is an essential step during the market authorization process of generic pharmaceutical formulations, for both human or veterinary use. The aim of the present study was to evaluate the pharmacokinetics of triclabendazole sulphoxide, the main metabolite of triclabendazole, and ivermectin in order to evaluate the bioavailability and bioequivalence of a novel sheep anthelmintic formulation of oral suspension for sheep treatment containing triclabendazole 50 mg/mL and ivermectin 1 mg/mL compared to the reference product. In order to determine relative bioavailability of the test product with respect to the reference product the study was conducted on 36 clinically healthy sheep, following an unicentric, randomized, cross-over, two-sequence, two-treatment and 14-day wash-out study design. For the determination of triclabendazole sulphoxide and ivermectin sheep plasma concentrations, two rapid, selective high performance liquid chromatography coupled with mass spectrometry (LC-MS/MS) methods were developed and validated. The measured plasma concentrations of triclabendazole sulphoxide and ivermectin were used for the pharmacokinetic analysis and the determination of bioequivalence between the test product with regards to the reference product. The noncompartmental analysis of the pharmacokinetic data for both triclabendazole sulphoxide and ivermectin showed similarities between first-order kinetics of the test and reference product. The relevant pharmacokinetic parameters (Cmax, AUClast, AUCtot) were determined and the bioequivalence between the test and reference product could be concluded.

scholarly journals Modest but Variable Effect of Rifampin on Steady-State Plasma Pharmacokinetics of Efavirenz in Healthy African-American and Caucasian Volunteers

2011 ◽  
Vol 55 (7) ◽  
pp. 3527-3533 ◽  
Author(s):  
Awewura Kwara ◽  
Karen T. Tashima ◽  
Julie B. Dumond ◽  
Pamela Poethke ◽  
Jaclyn Kurpewski ◽  
...  
Keyword(s):  
Body Weight ◽  
High Performance ◽  
Geometric Mean ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Time Curve ◽  
Variable Effect ◽  
Coefficients Of Variation ◽  
Tuberculosis Therapy

ABSTRACTEfavirenz-based antiretroviral regimen is preferred during rifampin-containing tuberculosis therapy. However, current pharmacokinetic data are insufficient to guide optimized concurrent dosing. This study aimed to better characterize the effects of rifampin on efavirenz pharmacokinetics. Subjects were randomized to receive 600 mg efavirenz/day or 600 mg efavirenz with 600 mg rifampin/day for 8 days, with plasma samples collected for pharmacokinetic analysis over 24 h on day 8. Treatments were then crossed over after at least a 2-week washout period, and procedures were repeated. Efavirenz concentrations were determined by high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were estimated by noncompartmental analysis. Efavirenz pharmacokinetic differences between treatment periods were evaluated by pairedttest. The coefficients of variation in efavirenz plasma AUC0-24(area under the concentration-time curve from 0 to 24 h) were 50% and 56% in the absence and presence of rifampin, respectively. Of the 11 evaluable subjects (6 white, 5 black; 6 women, 5 men), the geometric mean AUC0-24ratio on/off rifampin (90% confidence interval) was 0.82 (0.72, 0.92), with individual AUC0-24ratios varying from 0.55 to 1.18. Five subjects had a 24-hour efavirenz concentration (C24) of <1,000 ng/ml on rifampin. They were more likely to have received a lower dose in milligrams/kilogram of body weight and to have lower efavirenz AUC0-24values in the basal state. Although rifampin resulted in a modest reduction in efavirenz plasma exposure in subjects as a whole, there was high variability in responses between subjects, suggesting that efavirenz dose adjustment with rifampin may need to be individualized. Body weight and genetic factors will be important covariates in dosing algorithms.

Determination of Fenofibric Acid in Rat Plasma and its Application to a Comparative Pharmacokinetic Study of JW322 and Fenofibrate

Drug Research ◽  
2017 ◽  
Vol 67 (09) ◽  
pp. 534-538
Author(s):  
Tae Kim
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Relative Bioavailability ◽  
Rat Plasma ◽  
Reversed Phase ◽  
Pharmacokinetic Parameters ◽  
Fenofibric Acid ◽  
Ultraviolet Detector ◽  
Quantitation Limit

AbstractIn this study, a sensitive and reliable method for the quantitation of fenofibric acid in rat plasma was developed and validated using high performance liquid chromatography (HPLC). The plasma samples were prepared by deproteinization, and sildenafil was used as an internal standard. Chromatographic separation was achieved using a reversed-phase (C18) column. The mobile phase, 0.02 M ammonium acetate buffer:acetonitrile (35:65, v/v), was run at a flow rate of 1.0 mL/min, and the column eluent was monitored using an ultraviolet detector at 280 nm at room temperature. The retention times of sildenafil (an internal standard), and fenofibric acid were approximately 5.9 and 7.7 min, respectively. The quantitation limit of fenofibric acid in rat plasma was 0.03 μg/mL. Pharmacokinetic parameters of fenofibric acid was evaluated after oral (at doses of 20 mg/kg) administration of JW322 and fenofibrate in rats. After oral administration (20 mg/kg) of JW322, relative bioavailability was approximately 272.8% compared to fenofibrate.

Factors Affecting the Pharmacokinetic Characteristics of Rapacuronium 

1999 ◽  
Vol 90 (4) ◽  
pp. 993-1000 ◽  
Author(s):  
Dennis M. Fisher ◽  
Raymond Kahwaji ◽  
David Bevan ◽  
George Bikhazi ◽  
Robert J. Fragen ◽  
...  
Keyword(s):  
Plasma Clearance ◽  
Bolus Dose ◽  
Plasma Concentrations ◽  
Rapid Onset ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Single Bolus ◽  
Age Related ◽  
Single Bolus Dose

Background Rapacuronium is a new nondepolarizing muscle relaxant with rapid onset and offset. As part of a study to determine its neuromuscular effects, the authors sampled plasma sparsely to determine the influence of age, gender, and other covariates on its pharmacokinetic characteristics. Methods Of 181 patients receiving a single bolus dose of 0.5-2.5 mg/kg rapacuronium, 43 (aged 24-83 yr) had plasma sampled 3 or 4 times to determine plasma concentrations of rapacuronium and its metabolite, ORG9488. Pharmacokinetic analysis was performed using a population approach (mixed-effects modeling) to determine the influence of demographic characteristics and preoperative laboratory values on the pharmacokinetic parameters. Results Rapacuronium's weight-normalized plasma clearance was 7.03 x (1 - 0.0507 x (HgB - 13)) ml x kg(-1) x min(-1), where HgB is the patient's preoperative value for hemoglobin (g/100 ml); however, rapacuronium's blood clearance (11.4+/-1.4 ml x kg(-1) x min(-1), mean +/- SD) did not vary with hemoglobin. Rapacuronium's weight-normalized pharmacokinetic parameters were not influenced by age, gender, or other covariates examined. Plasma concentrations of ORG9488 were typically less than 14% those of rapacuronium during the initial 30 min after rapacuronium administration. Conclusions In this patient population, neither age nor gender influence elimination of rapacuronium. This finding contrasts to an age-related decrease in plasma clearance observed in a study of 10 healthy volunteers and in a pooled analysis of the pharmacokinetic data from 206 adults in multiple clinical studies. Even if ORG9488 has a potency similar to that of rapacuronium, its plasma concentrations after a single bolus dose of rapacuronium are sufficiently small to contribute minimally to neuromuscular blockade.

scholarly journals Relative bioavailability of rafoxanide following intraruminal and intra-abomasal administration in sheep

1999 ◽  
Vol 70 (2) ◽  
Author(s):  
G.E. Swan ◽  
H.A. Koeleman ◽  
H.S. Steyn ◽  
M.S.G. Mülders
Keyword(s):  
Peak Plasma ◽  
Plasma Concentrations ◽  
Relative Bioavailability ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Routes Of Administration ◽  
Parallel Group ◽  
Significant Difference ◽  
Rate Of Absorption ◽  
Lag Period

The bioavailability of rafoxanide was compared after intraruminal and intra-abomasal administration in healthy adult sheep (n = 6) in a single dose, 2 parallel group study at 7.5 mg/kg. Rafoxanide concentrations in plasma were measured by means of HPLC analysis. Primary pharmacokinetic parameters for bioavailability and disposition of rafoxanide in plasma for both routes of administration were determined by noncompartmental and non-linear, 1-compartmental pharmacokinetic analysis, respectively. Significantly (P < 0.05) higher peak plasma concentrations (cmax) of rafoxanide and a more rapid rate of absorption (c. 3.5 times) was observed in sheep after intra-abomasal (i-a) administration compared to intraruminal (i.r.) administration. A significantly (P < 0.05) longer lag period (tlag) before absorption (6.8 + 2.9 h) occurred after i.r. than after i-a treatment (1.9 + 0.6 h). There was no significant difference (P > 0.05) in AUC, MRT and in the rates of elimination (k10-HL and t1/2b) between the i.r. and i-a routes of administration. The results of the study demonstrated the important influence of the rumino-reticulum on absorption of rafoxanide in sheep.

scholarly journals Bioequivalence Study of Donepezil Hydrochloride Tablets in Healthy Male Volunteers

2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
Noppamas Rojanasthien ◽  
Siriluk Aunmuang ◽  
Nutthiya Hanprasertpong ◽  
Sukit Roongapinun ◽  
Supanimit Teekachunhatean
Keyword(s):  
High Performance ◽  
Reference Product ◽  
Bioequivalence Study ◽  
Pharmacokinetic Parameters ◽  
Two Phase ◽  
Test Product ◽  
Male Volunteers ◽  
Bioequivalence Range ◽  
The Mean ◽  
The Difference

The objective of this study was to investigate the bioequivalence of two formulations of 5 mg donepezil HCL tablets: Tonizep as the test and Aricept as the reference. The two products were administered as a single oral dose according to a randomized two-phase crossover with a 3-week washout period in 20 healthy Thai Male volunteers. After drug administration, serial blood samples were collected over a period of 216 hours. Plasma donepezil concentrations were measured by high performance liquid chromatography with UV detection. Pharmacokinetic parameters were analyzed based on noncompartmental analysis. The logarithmically transformed data of AUC0–∞ and were analyzed for 90% confidence intervals (CI) using ANOVA. The mean (90% CI) values for the ratio of AUC0–∞ and values of the test product over those of the reference product were 1.08 (1.02–1.14) and 1.08 (0.99–1.17), respectively (within the bioequivalence range of 0.8–1.25). The median for the test product was similar to that of the reference product (2.0 hr), and the 90% CI for the difference between the two preparations was –0.19 to 0.29 hr and within the bioequivalence range of ± 20% of the of the reference formulation. Our study demonstrated the bioequivalence of the two preparations.

scholarly journals The relative bioavailability of two formulations containing 10 mg Dapagliflozin assessed under fasting conditions in a randomized crossover study in healthy Caucasian subjects

2020 ◽  
Vol 66 (1) ◽  
pp. 30-34
Author(s):  
Monica Oroian ◽  
Diana Ioana Pop ◽  
Ana-Maria Gheldiu ◽  
Sandeep Bhardwaj ◽  
Adriana Marcovici ◽  
...  
Keyword(s):  
Single Dose ◽  
Reference Product ◽  
Area Under The Curve ◽  
Immediate Release ◽  
Relative Bioavailability ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Maximum Plasma ◽  
Open Label ◽  
Pharmaceutical Industries

AbstractObjective: The aim of the present study was to evaluate the relative bioavailability of two formulations containing 10 mg dapagliflozin in healthy Caucasian subjects under fasting conditions.Materials and Methods: Forty-eight healthy Caucasian subjects were enrolled in a single-dose, crossover, balanced, open label, randomized clinical trial, with two treatment, two periods and two sequences. The wash-out period was of 7 days and thirty-eight subjects completed both study periods. Each subject received a single dose of 10 mg dapagliflozin as the reference product Farxiga® (AstraZeneca Pharmaceuticals LP, USA) and the test product developed by Sun Pharmaceutical Industries, India. Dapagliflozin plasma levels were determined from blood samples collected in both study periods before and after dosing until 48 hours by using a validated LC-MS/MS method. For pharmacokinetic analysis of data, the non-compartmental method was used (Phoenix® WinNonlin 6.3). The statistical analysis was performed by SAS software 9.1.3 for the logarithmically transformed values of maximum plasma concentration and area under the curve.Results: The 90% confidence intervals for the evaluated pharmacokinetic parameters were found to be in the accepted interval for bioequivalence (80.00-125.00%).Conclusion: The 10 mg dapagliflozin immediate release tablet newly developed by Sun Pharmaceutical Industries, India, is bioequivalent with the reference product Farxiga® under fasted state of the subjects.

scholarly journals Determination and pharmacokinetic analysis of ticarcillin disodium–clavulanate potassium for injection in rat plasma by UPLC-ESI-MS/MS

2020 ◽  
Vol 48 (12) ◽  
pp. 030006052096782
Author(s):  
Moli Wang ◽  
Yanxia Gao ◽  
Xueli Liu ◽  
Jing Zhang ◽  
Qiang Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Rat Plasma ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Tandem Mass ◽  
Esi Ms ◽  
Linear Relationships ◽  
Ionization Tandem Mass Spectrometry

Objective To establish a specific and rapid ultra-high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC-ESI-MS/MS) method for measuring ticarcillin and clavulanate levels in rat plasma. Methods A Waters ACQUITY BEH C18 column (50 mm × 2.1 mm, 1.7 μm) and SCIEX QTRAP® LC-MS/MS System were used. Analyses were conducted to optimize the chromatographic and MS conditions, and the pharmacokinetic parameters of ticarcillin and clavulanate were assessed. Results Linear relationships were observed in the ranges of 10 to 10,000 ng/mL for ticarcillin R (r2 = 0.9967) 30 to 10,000 ng/mL for ticarcillin S (r2 = 0.9961), and 30 to 10,000 ng/mL for clavulanate (r2 = 0.9981). The average extraction recoveries of all compounds ranged from 86.9% to 96.4%. The pharmacokinetic parameters of the ticarcillin R and S isomers in rats were distinctive. The ticarcillin R and S isomers and clavulanate were rapidly absorbed in vivo. Ticarcillin S and clavulanate had similar elimination rates, whereas that of ticarcillin R was slower. Conclusion A UPLC-ESI-MS/MS method was developed and validated for the determination of ticarcillin and clavulanate in rat plasma.

Development of Validated Stability Indicating HPTLC Method for Assay of Ozagrel and its Pharmaceutical Formulations

2018 ◽  
pp. 36-48 ◽  
Author(s):  
Vishal N Kushare ◽  
Sachin S Kushare
Keyword(s):  
High Performance ◽  
Linear Regression Analysis ◽  
Pharmaceutical Formulations ◽  
Base Hydrolysis ◽  
Assay Method ◽  
Related Substance ◽  
Stability Indicating ◽  
Regular Production ◽  
Hptlc Method

The present paper describes stability indicating high-performance thin-layer chromatography (HPTLC) assay method for Ozagrel in bulk drugs. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of toluene: methanol: triethylamine (6.5: 4.0: 0.1 v/v/v). The system was found to give compact spot for Ozagrel (Rf value of 0.40 ± 0.010). Densitometric analysis of Ozagrel was carried out in the absorbance mode at 280 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.999 with respect to peak area in the concentration range 30 - 120 ng/spot. The developed HPTLC method was validated with respect to accuracy, precision, recovery and robustness. Also to determine related substance and assay determination of Ozagrel that can be used to evaluate the quality of regular production samples. The developed method can also be conveniently used for the assay determination of Ozagrel in pharmaceutical formulations. The limits of detection and quantitation were 4.069 and 12.332 ng/spot, respectively by height. Ozagrel was subjected to acid and alkali hydrolysis, oxidation, photochemical and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of Ozagrel in bulk drug and tablet formulation.

scholarly journals Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Linear Response ◽  
High Performance ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Caffeine Concentration ◽  
Real Samples ◽  
Wide Range ◽  
Potential Use

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

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