scholarly journals Comparative bioavailability study of phenytoin in healthy Nepalese volunteers

2019 ◽  
Vol 9 (1-s) ◽  
pp. 144-147
Author(s):  
DIllisher Rai ◽  
Gajendra Prasad Rauniar
Keyword(s):  
Plasma Concentration ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Elimination Rate ◽  
P Value ◽  
Maximum Plasma ◽  
Time Curve ◽  
Oral Tablet ◽  
Concentration Time ◽  
Plasma Concentration Time Curve

Our study aimed to assess and compare the bioavailability of Eptoin 100 mg and Epileptin 100mg tablets in Nepalese healthy volunteers. A randomized, two-treatment cross-over study with two weeks’ wash-out period was conducted in 12 healthy non-smoker and non-alcoholic Nepalese male volunteers over a period of 6 months in the department of Clinical Pharmacology and Therapeutic at B. P. Koirala Institute of Health Sciences, Dharan, Nepal after approval from the Institutional Review Committee. The participants were randomized using sealed envelope system and received a single 100 mg oral tablet of either of the formulations with a two week washout period. Blood samples were collected predose and at regular intervals postdose upto 72 hours. Plasma phenytoin levels were estimated by reverse phase high performance liquid chromatography. The analytical method was validated prior to the start of study. Cmax (Peak Plasma Concentration), Tmax (Time to achieve maximum Plasma Concentration), AUC0-72 (Area under plasma concentration time curve 0 to 72 hours), AUC0-∞ (Area under plasma concentration time curve 0 to ∞) and T½ (Elimination half-life) and Kel (Elimination rate constant) were calculated and 80-120% margin (90% confidence interval) was used to assess bioequivalence. ANOVA test was used to analyze the data at P-value of 0.05. All volunteers completed the study. The log-transformed values of Cmax, Tmax, AUC0-t, and AUC0-∞ of the both formulations were within the specified limits and were bioequivalent according to the regulatory definition of bioequivalence based on the rate and extent of absorption. Both products can be considered equally effective in medical practice. Keywords: Bioavailability, Bioequivalence, healthy volunteer, Nepal, phenytoin sodium.

scholarly journals Phase 1 Study of the Safety, Tolerability, and Pharmacokinetics of Vaborbactam and Meropenem Alone and in Combination following Single and Multiple Doses in Healthy Adult Subjects

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Christopher M. Rubino ◽  
Sujata M. Bhavnani ◽  
Jeffery S. Loutit ◽  
Elizabeth E. Morgan ◽  
Dan White ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Healthy Adult ◽  
Clinical Investigation ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Double Blind Study ◽  
Time Curve ◽  
Time Zero ◽  
Concentration Time ◽  
Plasma Concentration Time Curve

ABSTRACTMeropenem-vaborbactam is a fixed combination of the novel β-lactamase inhibitor vaborbactam and the carbapenem antibiotic meropenem, developed for the treatment of serious infections caused by drug-resistant Gram-negative bacteria. The safety, tolerability, and pharmacokinetics (PK) of vaborbactam and meropenem following single and multiple ascending doses of each study drug administered alone or combined were evaluated in 76 healthy adult subjects in a randomized, placebo-controlled, double-blind study. Subjects were enrolled in 1 of 5 dose cohorts (receiving 250 to 2,000 mg vaborbactam and/or 1,000 to 2,000 mg meropenem) alone or in combination. No subjects discontinued the study due to adverse events (AEs), and no serious AEs were observed. The pharmacokinetics of meropenem and vaborbactam were similar when given alone or in combination; all evaluated plasma PK exposure measures (peak plasma concentration, area under the plasma concentration-time curve [AUC] from time zero to the last measurable concentration area under the plasma concentration-time curve, and AUC from time zero to infinity) were similar for the study drugs alone versus those in combination, indicating no pharmacokinetic interaction between meropenem and vaborbactam. Across all treatments, 47 to 64% of an administered meropenem dose and 75 to 95% of vaborbactam was excreted unchanged in the urine over 48 h postdose. Meropenem and vaborbactam, when given alone or in combination, have similar pharmacokinetic properties, with no plasma or urine PK drug-drug interactions, and are well tolerated. These findings supported further clinical investigation of the combination product. (This study is registered at ClinicalTrials.gov under registration no. NCT01897779.)

Exposure to Retinoic Acids in Non-Pregnant Women Following High Vitamin A Intake with a Liver Meal

2005 ◽  
Vol 75 (3) ◽  
pp. 187-194 ◽  
Author(s):  
Hartmann ◽  
Brørs ◽  
Bock ◽  
Blomhoff ◽  
Bausch ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Vitamin A ◽  
Safety Concern ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Pregnant Female ◽  
Time Curve ◽  
High Vitamin ◽  
Concentration Time ◽  
Plasma Concentration Time Curve

Animal liver is a rich source of vitamin A. Due to retinoic acid (RA) metabolites, vitamin A has a teratogenic potential and women are generally advised to avoid or to limit the consumption of liver during pregnancy. In a recent study in non-pregnant female volunteers following single and repeated doses of up to 30,000 IU/day of vitamin A as a supplement, the plasma concentration time curve of all-trans RA acid showed a diurnal-like profile. But, the overall exposure (AUC24h) remained essentially unaltered whereas AUC24h increased linearly with dose for 13-cis and 13-cis-4-oxo RA. The current study in non-pregnant female volunteers showed that a single high vitamin A intake with a liver meal (up to 120,000 IU) exhibited a similar diurnal-like plasma concentration time curve for all-trans RA and its overall exposure remained also unaltered, despite a temporary two-fold increase in peak plasma concentration. Concentrations of 13-cis and 13-cis-4-oxo RA increased several-fold after a liver meal, and exposure (AUC24h) increased three- to five-fold. Pooling our results with data in the literature revealed a linear relation between the mean AUC24h of 13-cis and 13-cis-4-oxo RA and vitamin A intake with liver. Metabolism to all-trans RA of vitamin A with liver seems not to be of safety concern. However, the observed increase of plasma concentrations and the dose-dependent increase in exposure to 13-cis and 13-cis-4-oxo RA support the current safety recommendations on vitamin A intake and suggest that women should be cautious regarding their consumption of liver-containing meals during pregnancy.

Pharmacokinetics of an immunomodulating dose of levamisole in weaned pigs

2013 ◽  
Vol 61 (3) ◽  
pp. 376-382
Author(s):  
Jelena Šuran ◽  
Dubravka Flajs ◽  
Maja Peraica ◽  
Andreja Prevendar Crnić ◽  
Marcela Šperanda ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Area Under The Curve ◽  
Maximum Plasma ◽  
Weaned Pigs ◽  
Time Curve ◽  
Treatment Groups ◽  
Parallel Design ◽  
Concentration Time ◽  
Plasma Concentration Time Curve ◽  
Crossbred Pigs

Levamisole has been shown to stimulate the immune response in immunocompromised humans and animals. However, its use as an adjuvant in immunocompromised weaned pigs prone to colibacillosis has only been experimentally tested but not yet officially approved. Therefore, the aim of these studies was to study the pharmacokinetics (PK) of an immunomodulating dose of levamisole in weaned pigs. For that purpose, 20 weaned crossbred pigs were divided into two treatment groups. In this parallel-design study, a single dose of levamisole (2.5 mg/kg body weight) was administered by the intramuscular (i.m.) or oral (p.o.) route. Statistically significant differences between the i.m. and p.o. routes in terminal beta rate constant (β), maximum plasma concentration (Cmax), area under the curve (AUC) for plasma concentration-time curve from time zero to infinity (AUC0-inf), area under the plasma concentration-time curve from time 0 to the last quantifiable time point (AUC0-t) were determined. Further research is needed to establish a relationship between the PK and the immunomodulating effect of levamisole in pigs.

Interaction of Metoprolol, Propranolol and Atenolol with Cimetidine

1982 ◽  
Vol 63 (s8) ◽  
pp. 451s-453s ◽  
Author(s):  
W. Kirch ◽  
H. Spahn ◽  
H. Köhler ◽  
E. Mutschler
Keyword(s):  
Plasma Concentration ◽  
Healthy Volunteers ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Concurrent Administration ◽  
Time Curve ◽  
Concentration Time ◽  
Plasma Concentration Time Curve

1. Pharmacokinetics of metoprolol, propranolol and atenolol were investigated in six healthy volunteers after 7 days of oral monotherapy with these drugs and after 7 days concurrent administration, with each of these β-adrenoceptor antagonists with cimetidine. 2. Cimetidine did not interact with atenolol, whereas mean peak plasma concentrations of metoprolol were increased by 70%, and those of propranolol by 95% with concurrent administration of cimetidine (P < 0.05). 3. The area under the plasma concentration-time curve for propranolol and metoprolol was similarly increased (P < 0.05).

Comparative Bioavailability of a Microsize and Ultramicrosize Griseofulvin Formulation in Man

1982 ◽  
Vol 10 (4) ◽  
pp. 274-277 ◽  
Author(s):  
C Lin ◽  
J Lim ◽  
C DiGiore ◽  
R Gural ◽  
bS Symchowicz
Keyword(s):  
Plasma Concentration ◽  
Maximum Plasma Concentration ◽  
Maximum Plasma ◽  
Healthy Male ◽  
Time Curve ◽  
Concentration Time ◽  
Comparative Bioavailability ◽  
Plasma Concentration Time Curve ◽  
Randomized Crossover Study ◽  
Curve Maximum

The bioavailability of 500 mg of a microsize formulation of griseofulvin has been compared to two new ultramicrosize griseofulvin formulations, two 165 mg tablets and a 330 mg tablet, in sixteen healthy, male, volunteers in a randomized crossover study design. Based on the griseofulvin plasma levels measured at specified times over a 48-hour period, the major bioavailability parameters (i.e., area under plasma concentration-time curve, maximum plasma concentration, and time to reach maximum plasma concentration) were determined and statistically evaluated. The results showed that one 330 mg ultramicrosize tablet is bioequivalent to two 165 mg ultramicrosize griseofulvin tablets and that either ultramicrosize griseofulvin dosage regimen is bioequivalent to 500 mg of the microsize griseofulvin formulation.

scholarly journals Multiple-Dose Safety, Tolerability, and Pharmacokinetics of Oral Nemonoxacin (TG-873870) in Healthy Volunteers

2010 ◽  
Vol 54 (1) ◽  
pp. 411-417 ◽  
Author(s):  
David T. Chung ◽  
Cheng-Yuan Tsai ◽  
Shu-Jen Chen ◽  
Li-Wen Chang ◽  
Chi-Hsin R. King ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Healthy Volunteers ◽  
Bacterial Infections ◽  
Maximum Plasma Concentration ◽  
Maximum Plasma ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Atypical Pathogens ◽  
Plasma Concentration Time Curve

ABSTRACT Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with broad-spectrum activities against Gram-positive and Gram-negative aerobic, anaerobic, and atypical pathogens, as well as against methicillin-resistant Staphylococcus aureus, vancomycin-resistant S. aureus, and multiple-resistant bacterial pathogens. We conducted a randomized, double-blind, placebo-controlled, dose-escalating study to ascertain the safety, tolerability, and pharmacokinetics of nemonoxacin. We enrolled 46 healthy volunteers and used a once-daily oral-dosing range of 75 to 1,000 mg for 10 days. Additionally, the food effect was evaluated in subjects in the 500-mg cohort. Nemonoxacin was generally safe and well tolerated, with no significant changes in the clinical laboratory tests or electrocardiograms. Adverse effects, including headache, contact dermatitis, and rash, were mild and resolved spontaneously. Nemonoxacin was rapidly absorbed within 2 h postdosing, and generally, a steady state was reached after 3 days. The maximum plasma concentration and the area under the plasma concentration-time curve were dose proportional over the dosing range. The elimination half-life was approximately 7.5 h and 19.7 h on days 1 and 10, respectively. Approximately 37 to 58% of the drug was excreted in the urine. Food affected the pharmacokinetics, with decreases in the maximum plasma concentration and area under the plasma concentration-time curve of 46% and 27%, respectively. However, the free AUC/MIC90 of nemonoxacin was more than 100 under both the fasting and fed conditions, predicting the efficacy of nemonoxacin against most of the tested pathogens. In conclusion, the results support further clinical investigation of once-daily nemonoxacin administration for antibiotic-sensitive and antibiotic-resistant bacterial infections.

scholarly journals Atogepant and sumatriptan: no clinically relevant drug–drug interactions in a randomized, open-label, crossover trial

2021 ◽  
Author(s):  
Ramesh Boinpally ◽  
Abhijeet Jakate ◽  
Matthew Butler ◽  
Antonia Periclou
Keyword(s):  
Plasma Concentration ◽  
Crossover Trial ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Geometric Mean ◽  
Open Label ◽  
Time Curve ◽  
Concentration Time ◽  
Pharmacokinetic Interactions ◽  
Randomized Crossover Study

Aim: To evaluate pharmacokinetic interactions of atogepant with sumatriptan, an open-label, randomized, crossover study was conducted. Patients & methods: Thirty healthy adults received atogepant 60 mg, sumatriptan 100 mg, or coadministered drugs. Primary end point was geometric mean ratios (GMRs) and 90% CIs of interventions for area under the plasma concentration–time curve from time 0 to t (AUC0-t) or infinity (AUC0-∞) and peak plasma concentration (Cmax). Results: Atogepant GMRs for AUC0-t and AUC0-∞ versus with sumatriptan were within 90% CI 0.80–1.25, indicating no interaction; atogepant Cmax was reduced by 22% (GMR: 0.78; 90% CI: 0.69–0.89) with sumatriptan. Sumatriptan GMRs for AUC0-t, AUC0-∞ and Cmax versus with atogepant were within 90% CI 0.80–1.25. Conclusion: Atogepant with sumatriptan had no clinically relevant pharmacokinetic interactions.

scholarly journals Pharmacokinetics of toltrazuril and its metabolites toltrazuril sulphoxide and toltrazuril sulphone in pregnant and non-pregnant goats

2021 ◽  
Vol 90 (4) ◽  
pp. 383-390
Author(s):  
Sara T. Elazab ◽  
Nahla S. Elshater ◽  
Ahmed E. Elweza
Keyword(s):  
Plasma Concentration ◽  
Volume Of Distribution ◽  
Maximum Plasma ◽  
Time Curve ◽  
Concentration Time ◽  
Elimination Half ◽  
Plasma Concentration Time Curve ◽  
Group 2 ◽  
Post Therapy ◽  
Group 1

The pharmacokinetic characteristics of toltrazuril (TZR) and its metabolites toltrazuril sulphoxide (TZR.SO) and toltrazuril sulphone (TZR.SO2) were assessed in non-pregnant and pregnant goats. Ten healthy Baladi female goats were allocated into two groups (n = 5 per group): non-pregnant goats (group 1) and pregnant goats at 2–3 months of gestation (group 2). Toltrazuril was administered once orally to all goats at 20 mg/kg. Plasma samples were collected at 0 (before TZR administration), 0.5, 1, 2, 4, 6, 8, 12, 16, 24, 48, 72 h and 5, 7, 9, 12, 16, 20, 24, 27, 30, and 35 days post therapy to measure the concentrations of TZR and its metabolites. In pregnant goats, the maximum plasma concentration (Cmax), time to reach Cmax (Tmax), and the area under the plasma concentration-time curve from time zero to the last sample (AUC0-last) of TZR were significantly higher (P < 0.05) compared to the non-pregnant ones, whereas the volume of distribution (Vz_F_obs) and clearance (Cl_F_obs) were significantly lower (P < 0.05) in pregnant goats. No significant differences were observed in the elimination half-life (T1/2λz), and mean residence time (MRT) between the two groups. In non-pregnant goats, TZR.SO and TZR.SO2 could be detected in plasma until 12 and 30 days, respectively; whereas in pregnant goats, they were quantified up to 16 and 35 days, respectively. Conclusively, TZR was well absorbed and rapidly metabolized to TZR.SO and TZR.SO2, after oral dosing in goats. Pregnancy caused significant alterations in some of the pharmacokinetic indicators of TZR and its metabolites in goats.

scholarly journals Enhanced Oral Bioavailability of Domperidone with Piperine in Male Wistar Rats: Involvement of CYP3A1 and P-gp Inhibition

2017 ◽  
Vol 20 ◽  
pp. 28 ◽  
Author(s):  
Bhargavi Latha Athukuri ◽  
Prasad Neerati
Keyword(s):  
Plasma Concentration ◽  
Oral Bioavailability ◽  
Wistar Rats ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Elimination Rate ◽  
Intestinal Transport ◽  
Control Group ◽  
Maximum Plasma ◽  
Male Wistar Rats

Purpose: Domperidone is a commonly used antiemetic drug. The oral bioavailability of domperidone is very low due to its rapid first pass metabolism in the intestine and liver. Piperine, the main alkaloid present in black pepper has been reported to show inhibitory effects on Cytochrome P-450 (CYP-450) enzymes and P-glycoprotein (P-gp). In the present study we investigated the effect of piperine pretreatment on the intestinal transport and oral bioavailability of domperidone in male Wistar rats. Methods: The intestinal transport of domperidone was evaluated by an in-vitro non-everted sac method and in-situ single pass intestinal perfusion (SPIP) study. The oral pharmacokinetics of domperidone was evaluated by conducting oral bioavailability study in rats. Results: A statistically significant improvement in apparent permeability (Papp) was observed in rats pretreated with piperine compared to the respective control group. The effective permeability (Peff) of domperidone was increased in the ileum of the piperine treated group. Following pretreatment with piperine, the peak plasma concentration (Cmax) and area under the concentration- time curve (AUC) were significantly increased. A significant decrease in time to reach maximum plasma concentration (Tmax), clearance and elimination rate constant (Kel) was observed in rats pretreated with piperine. Conclusions: Piperine enhanced the oral bioavailability of domperidone by inhibiting CYP3A1 and P-gp in rats. This observation suggests the possibility that the combination of piperine with other CYP3A4 and P-gp dual substrates may also improve bioavailability. Further clinical studies are recommended to verify this drug interaction in human volunteers and patients. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

Methotrexate pharmacokinetics following administration of recombinant carboxypeptidase-G2 in rhesus monkeys.

1992 ◽  
Vol 10 (8) ◽  
pp. 1359-1364 ◽  
Author(s):  
P C Adamson ◽  
F M Balis ◽  
C L McCully ◽  
K S Godwin ◽  
D G Poplack
Keyword(s):  
Plasma Concentration ◽  
Rhesus Monkeys ◽  
Alternative Form ◽  
High Dose ◽  
Time Curve ◽  
Carboxypeptidase G2 ◽  
Concentration Time ◽  
Bacterial Enzyme ◽  
Plasma Pharmacokinetics ◽  
Plasma Concentration Time Curve

PURPOSE Carboxypeptidase-G2 (CPDG2) is a bacterial enzyme that rapidly hydrolyzes methotrexate (MTX) into inactive metabolites. As an alternative form of rescue after high-dose MTX (HDMTX), CPDG2 has more potential advantages than standard leucovorin (LV) rescue. In this study, the plasma pharmacokinetics of MTX with and without CPDG2 were evaluated in adult rhesus monkeys. MATERIALS AND METHODS The plasma pharmacokinetics of MTX were determined in groups of animals that had received a 300-mg/m2 loading dose of MTX followed by a 60-mg/m2/h infusion during an 18-hour period. One group received CPDG2 at the end of the infusion, and the other group served as a control. Two additional animals with high titers of anti-CPDG2 antibody also were studied. RESULTS During infusion, the steady-state MTX plasma concentration was 11.3 +/- 4.8 mumol/L. Without CPDG2, the postinfusion plasma MTX concentration remained above 0.1 mumol/L for more than 6 hours. After the administration of 50 U/kg of CPDG2, plasma MTX concentrations decreased to nontoxic levels (less than 0.05 mumol/L) within 30 minutes. The initial half-life (t1/2 alpha) of MTX decreased from 5.8 +/- 2.1 minutes to 0.7 +/- 0.02 minutes after enzyme administration. The postinfusion area under the plasma concentration time curve of MTX was 301 +/- 171 mumol/L/min without CPDG2 compared with 19.6 +/- 6.1 mumol/L/min with CPDG2. The immunogenicity studies performed indicated that although animals developed anti-CPDG2 antibodies, none of them manifested allergic symptoms. The effectiveness of CPDG2 was diminished but not eliminated in animals with high titers of anti-CPDG2 antibody. CONCLUSIONS CPDG2 is capable of rapidly decreasing plasma MTX concentrations to nontoxic levels. The administration of CPDG2 seems safe, well tolerated, and it may be useful as an alternative to LV rescue.

Sign in / Sign up

Export Citation Format

Share Document