Search results for "pharmacokinetic"
showing 10 items of 474 documents
The Influence of Chitosan on the Oral Bioavailability of Acyclovir-a Comparative Bioavailability Study in Humans
2015
Purpose The effects of chitosan hydrochloride on the oral absorption of acyclovir in humans were studied to confirm the absorption enhancing effects reported for in vitro and rat studies, respectively. Methods A controlled, open-label, randomized, 3-phase study was conducted in 12 healthy human volunteers. Zovirax 200 mg dispersible tablets co-administered with doses of 400 and 1000 mg chitosan HCl were compared with Zovirax only. Results The expected increased absorption of acyclovir was not observed. On the contrary, mean area under the plasma concentration-time curve (AUC0-12 h) and maximal plasma concentration (Cmax) decreased following concomitant chitosan intake (1402 versus 1017 and …
Influence of green and black tea on folic acid pharmacokinetics in healthy volunteers: potential risk of diminished folic acid bioavailability
2008
Previous in vitro studies using Caco-2 cell monolayers suggested a possible interaction between green and black tea and folic acid at the level of intestinal absorption. The main purpose of the present study was to investigate a possible pharmacokinetic interaction between tea and folic acid in healthy volunteers. In an open-labeled randomized cross-over study, the pharmacokinetic interaction between tea and folic acid (0.4 mg and 5 mg) was investigated in healthy volunteers. Water was used as the reference drink. Subjects ingested 0.4 mg folic acid tablets with water, green or black tea (0.3 g extract/250 ml) or 5 mg folic acid tablets with water or green tea (0.3 g extract/250 ml). Blood …
Body mass index as a determinant of clozapine plasma concentrations: A pharmacokinetic-based hypothesis
2021
Background: Knowledge regarding the impact of body composition measures on pharmacokinetics of antipsychotics is limited. Aims: Our aim was to investigate the impact of body weight and body mass index on clozapine pharmacokinetics using a therapeutic drug monitoring database. Methods: A large therapeutic drug monitoring dataset of clozapine plasma concentrations considering three patient subgroups was analysed: a control group (CLZ0, 20–30 kg/m2, n=266), a group with high body mass index (CLZhigh, body mass index ⩾30 kg/m2, n=162) and with low body mass index values (CLZlow, body mass index <20 kg/m2, n=27). Comparisons of plasma and dose-adjusted plasma concentrations (C/D) of clozapine…
The role of cytochrome P450 2D6 in the metabolism of moclobemide.
1996
The metabolic fate of moclobemide (Ro 11-1163), a new reversible and selective inhibitor of monoamine oxidase type A (MAO-A), has been assessed in a pilot study in 2 debrisoquine poor metabolizers (PM) and 4 extensive metabolizers (EM) after multiple oral dosings of moclobemide with and without co-medication of dextromethorphan. Absorption and disposition parameters were not different between PM and EM. Concurrent application of dextromethorphan, a selective substrate of CYP2D6, did not affect the pharmacokinetics of moclobemide. These results indicate that the cytochromal isoenzyme CYP2D6 does not play a major role in the metabolic degradation of moclobemide. Limited CYP2D6 activities beca…
A phase I pharmacokinetic and pharmacodynamic study of dalotuzumab (MK-0646), an anti-insulin-like growth factor-1 receptor monoclonal antibody, in p…
2011
Abstract Purpose: Insulin-like growth factor-1 receptor (IGF-1R) mediates cellular processes in cancer and has been proposed as a therapeutic target. Dalotuzumab (MK-0646) is a humanized IgG1 monoclonal antibody that binds to IGF-1R preventing receptor activation. This study was designed to evaluate the safety and tolerability of dalotuzumab, determine the pharmacokinetic (PK) and pharmacodynamic (PD) profiles, and identify a recommended phase II dose. Experimental Design: Patients with tumors expressing IGF-1R protein were allocated to dose-escalating cohorts of three or more patients each and received intravenous dalotuzumab weekly, every 2 or 3 weeks. Plasma was collected for PK analysis…
Phase I Pharmacokinetic/Pharmacodynamic Study of MLN8237, an Investigational, Oral, Selective Aurora A Kinase Inhibitor, in Patients with Advanced So…
2012
Abstract Purpose: Aurora A kinase (AAK) is a key regulator of mitosis and a target for anticancer drug development. This phase I study investigated the safety, pharmacokinetics, and pharmacodynamics of MLN8237 (alisertib), an investigational, oral, selective AAK inhibitor, in 59 adults with advanced solid tumors. Experimental Design: Patients received MLN8237 once daily or twice daily for 7, 14, or 21 consecutive days, followed by 14 days recovery, in 21-, 28-, or 35-day cycles. Dose-limiting toxicities (DLT) and the maximum-tolerated dose (MTD) for the 7- and 21-day schedules were determined. Pharmacokinetic parameters were derived from plasma concentration–time profiles. AAK inhibition in…
Phase I Pharmacokinetic and Pharmacodynamic Dose-Escalation Study of RG7160 (GA201), the First Glycoengineered Monoclonal Antibody Against the Epider…
2011
Purpose We conducted a phase I dose-escalation study to characterize the safety, efficacy, pharmacokinetic (PK), and pharmacodynamic properties of RG7160 (GA201), a humanized and glycoengineered immunoglobulin G1 anti–epidermal growth factor receptor (EGFR) monoclonal antibody with enhanced antibody-dependent cell-mediated cytotoxicity. Patients and Methods Seventy-five patients with advanced EGFR-positive solid tumors received RG7160 (50 to 1,400 mg) administered every week, every 2 weeks, or every 3 weeks. Dose escalation followed a three-plus-three trial design. Results No maximum-tolerated dose was reached for any dosing schedule. Common adverse events (AEs) included rash (80% of patien…
New levothyroxine formulation meeting 95–105% specification over the whole shelf-life: results from two pharmacokinetic trials
2016
Small levothyroxine (L-T4) dose changes can lead to significant clinical effects. To ensure thyroid hormone levels are safely maintained, authorities are increasingly adopting stricter potency specifications for L-T4, the most stringent of these being 95-105% of the labeled dose over the whole shelf-life. Levothyroxine sodium (Euthyrox, Eutirox, Lévothyrox ) has been reformulated, and two studies performed, to ensure bioequivalence to the currently marketed formulation and dosage form proportionality of the new formulation.The bioequivalence study was an open-label, randomized, single-dose, two-period, two-sequence crossover comparing the highest dosage strengths of the currently marketed a…
Expanded gentamicin volume of distribution in critically ill adult patients receiving total parenteral nutrition
1995
Aminoglycoside antibiotics distribute into the extracellular fluid compartment and are eliminated by the kidney via glomerular filtration. Malnutrition and total parenteral nutrition influence the fluid and electrolyte status of the patient, and cause organ changes. The purpose of this clinical study was to characterize the kinetic behaviour of gentamicin in the parenterally fed critically ill adult patient. Eighty-six critically ill adult patients treated with gentamicin for severe Gram-negative infections were enrolled in the study (mean +/- SD): age, 60 +/- 14 years; weight, 69.4 +/- 10.2 kg; height, 163 +/- 10 cm; 22 females and 64 males. Four study groups were defined (2 x 2): total pa…
Relationship between rheological properties, in vitro release and in vivo equivalency of topical formulations of diclofenac.
2019
Determination of bioequivalence remains a challenge in generic topical drug development. To support pharmacokinetic studies, strategies to demonstrate microstructure sameness of the products being compared include in vitro evaluations, such as the comparison of rheological properties, droplet size and in vitro release rates. Nevertheless, defining the appropriate acceptance range to consider equivalence between test and reference formulation is complex. To shed more light into this issue, in vitro release and rheological properties were compared to in vivo bioequivalence data (systemic blood measurements within a clinical trial) after topical application of a single dose. Test and reference…