Search results for "Pharmacokinetic"
showing 10 items of 474 documents
Pharmacokinetics of acute and sub-chronic aripiprazole in P-glycoprotein deficient mice
2010
Abstract Background P-glycoprotein (P-gp), an efflux transporter localized in the blood–brain barrier, limits the access of multiple xenobiotics to the central nervous system (CNS). For the new antipsychotic aripiprazole and its active metabolite dehydroaripiprazole differences in disposition in blood and brain were investigated after acute and sub-chronic administration in a P-gp knockout mouse model. Methods Serum and brain concentrations of both drugs were measured at several time points 1–24 h after i.p. injection of 10 mg/kg aripiprazole and after 11 days of sub-chronic administration in several tissues. Moreover, the expression of P-gp was determined by Western blot analysis after sub…
Determination of the technetium-99m mercaptoacetyltriglycine plasma clearance in children by means of a single blood sample: a multicentre study
1993
A multicentre European study was undertaken in order to determine a reasonable algorithm allowing the determination of overall technetium-99m mercaptoacetyltriglycine clearance using a single blood sample. Employing multiple blood sample clearance as a reference method, it was shown that an acceptable estimation of the MAG3 renal clearance could be obtained using a blood sample taken at any time between 30 and 40 min after tracer injection. After correction for body surface area, comparison of clearance determined using (a) the single blood sample and (b) the multiple blood samples provided a coefficient of correlation of 0.949 and an SEE of 27 ml/min. This algorithm is valid for clearance …
Anthropometric measurements of the body composition of cancer patients determine the precise role of the body surface area and the calculation of the…
2012
The calculation of an accurate dose of chemotherapy for oncological patients reduces the possible medication errors and the toxicity of the body and so it improves the outcome of the treatment (survival). In oncological practice for the calculation of the dose of chemotherapy the human body surface area (BSA) is used. The human body surface area is determined by derived formulas, but it is not directly linked to the pharmacokinetics of the drugs. Pharmacokinetic studies have demonstrated that for the calculation of the chemotherapy dose the actual body weight should be taken into account rather than the ideal one. In the therapeutic dose determination the body fat mass has essential signifi…
Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Moxifloxacin Hydrochloride.
2020
Abstract In this monograph, literature data is reviewed to evaluate the feasibility of waiving in vivo bioequivalence testing and instead applying the Biopharmaceutics Classification System (BCS) based methods to the approval of immediate-release solid oral dosage forms containing moxifloxacin hydrochloride as the sole active pharmaceutical ingredient. To facilitate the feasibility decision, solubility and permeability and dissolution characteristics in the context of the BCS, therapeutic index, therapeutic use, pharmacokinetic parameters, bioequivalence/bioavailability issues, drug-excipient interactions and other relevant data were taken into consideration. Moxifloxacin is a BCS class I d…
Biotransformation in vitro of the 22R and 22S epimers of budesonide by human liver, bronchus, colonic mucosa and skin.
2001
The pharmacological effects of glucocorticoids are greatly influenced by their pharmacokinetic properties. In the present report, the in vitro biotransformation of the 22R and 22S epimers of the topical steroid budesonide was studied in the S-9 fraction of human liver, bronchus, skin and colonic mucosa. The disappearance of unchanged epimers of budesonide was measured during 90 min of incubation by high performance liquid chromatography. The rate of disappearance was high in human liver while little biotransformation occurred in bronchial tissue and colonic mucosa, and none was detected in the skin. A marked decay of the initial concentration of unchanged budesonide epimers was noticed afte…
24-h efficacy and pharmacokinetics of tiotropium Respimat® 5 μg in patients with asthma
2015
Background: Once-daily tiotropium Respimat® (tioR) add-on therapy has demonstrated efficacy in patients with moderate symptomatic asthma. Aim and Objectives: To investigate whether dosing regimen (QD vs BID) affected 24-h bronchodilator efficacy and exposure of tioR. Methods: 2 randomised, double-blind, crossover trials (trial 1, NCT01152450 [placebo-controlled]; trial 2, NCT01696071); 4-week treatments of tioR 5 µg QD, 2.5 µg BID and placebo Respimat® (pboR) added to medium-dose ICS (400-800 µg budesonide or equivalent). Primary end point (Week 4): area under the curve response for FEV1 (FEV1 AUC(0-24h)) (trial 1, tioR vs pboR; trial 2, QD vs BID). Pharmacokinetic end points (steady state)…
1023 – Therapeutic drug-monitoring of bupropion for depression
2013
Introduction Therapeutic Drug-Monitoring (TDM) for bupropion is limited by bupropion's instability at room temperature and by the absence of a well-defined therapeutic reference range. Further it is unclear to what extent bupropion and its metabolites contribute to therapeutic effects, though hydroxybupropion seems to account for the major antidepressant effects. Aim The aim of this examination was to check if measurement of only hydroxybupropion is useful to guide the antidepressant therapy with bupropion. Methods Hydroxybupropion plasma levels were measured by high performance liquid chromatography with ultra violet detection and related to therapeutic effects measured by the Clinical Glo…
A systematic review and combined analysis of therapeutic drug monitoring studies for longacting risperidone
2017
Introduction: This systematic review of therapeutic drug monitoring (TDM) identifies three long-acting injectable (LAI) risperidone formulations. Areas covered: Limited data is available on two formulations (RBP-7000 and in Situ Microparticle), but 20 TDM articles on the microsphere formulation were found. Risperidone TDM includes the serum concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone, used for calculating: 1) the risperidone/9-hydroxyrisperidone (R/9-OH-R) ratio (a measure of CYP2D6; values >1 are indicative of a CYP2D6 poor metabolizer) and 2) the total risperidone concentration-to-dose (C/D) ratio (a measure of risperidone clearance with a normal value…
PHEA-graft-polymethacrylate supramolecular aggregates for protein oral delivery
2013
Abstract Salmon calcitonin (sCT) is characterized by a poor oral availability. A new copolymer, β-poly(N-2-hydroxyethyl)-graft-{N-2-ethylene[2-poly(methacrylic acid sodium salt)isobutyrate]}- d , l -aspartamide (PHEA-IB-p(MANa + )), was designed for the oral administration of sCT through the formation of supramolecular aggregates (SAs) based on electrostatic interactions. Several sCT/PHEA-IB-p(MANa + ) weight ratios were characterized by turbidimetry, DLS, zeta potential, and microscopy analysis. After the incubation of sCT/PHEA-IB-p(MANa + ) complex with digestive enzymes, 10% (w/w) of loaded sCT was released in the native form. In vitro investigation was carried out to determine the copol…
Whole-body pharmacokinetics of HDAC inhibitor drugs, butyric acid, valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by …
2013
The fatty acids, n-butyric acid (BA), 4-phenylbutyric acid (PBA) and valproic acid (VPA, 2-propylpentanoic acid) have been used for many years in the treatment of a variety of CNS and peripheral organ diseases including cancer. New information that these drugs alter epigenetic processes through their inhibition of histone deacetylases (HDACs) has renewed interest in their biodistribution and pharmacokinetics and the relationship of these properties to their therapeutic and side effect profiles. In order to determine the pharmacokinetics and biodistribution of these drugs in primates, we synthesized their carbon-11 labeled analogues and performed dynamic positron emission tomography (PET) in…