Search results for "Pharmacokinetics"
showing 10 items of 458 documents
Column switching and high-performance liquid chromatography in the analysis of amitriptyline, nortriptyline and hydroxylated metabolites in human pla…
1992
A column-switching system for the direct injection of plasma or serum samples, followed by isocratic high-performance liquid chromatography and ultraviolet detection, is described for the simultaneous quantitation of the tricyclic antidepressant amitriptyline, its demethylated metabolite nortriptyline and the E- and Z-isomers of 10-hydroxyamitriptyline and 10-hydroxynortriptyline. The method included adsorption of amitriptyline and metabolites on a reversed-phase C8 clean-up column (10 microns; 20 mm x 4.6 mm I.D.), washing of unwanted material to waste and, after on-line column-switching, separation on a cyanopropyl analytical column (5 microns; 250 mm x 4.6 mm I.D.). The compounds of inte…
Effect of body weight on the volume of distribution of theophylline.
1988
The volume of distribution (Vd) of theophylline and the relevant aminophylline loading dose (LD) are usually calculated on the basis of total body weight (TBW). In obese subjects it has been suggested that lean or ideal body weight (IBW) is the best predictor. In a sample of 40 acutely ill asthmatic patients (aged 22 to 78 yr, weighing 45 to 176 kg) we measured Vd and found that (1) it increases with TBW, (2) it cannot be accurately predicted from either TBW or IBW alone by a simple regression analysis. Power functions have been usefully applied in comparing the pharmacokinetics of animal species, including humans, with different body mass. In our sample, data were best fitted by the equati…
Hydroxychloroquine in children with interstitial (diffuse parenchymal) lung diseases
2014
Summary Hydroxychloroquine (HCQ) is one of the drugs frequently used for the treatment of interstitial lung disease (ILD) in children (chILD). This use is off-label and studies to analyze the effect and safety of HCQ in chILD are lacking. Therefore, a literature research on the usage of chloroquine (CQ) and HCQ in these conditions was done. Eighty-five case reports and small series in the period from 1984 to 2013 were identified in which children with different diagnoses of ILD were treated with CQ or HCQ, sometimes in combination with other medication including steroids. A favorable response to HCQ or CQ was reported in 35 cases, whereas in the other cases the effect was negative or not cl…
Evaluation of the Physicochemical Properties of the Iron Nanoparticle Drug Products: Brand and Generic Sodium Ferric Gluconate
2021
Complex iron nanoparticle-based drugs are one of the oldest and most frequently administered classes of nanomedicines. In the US, there are seven FDA-approved iron nanoparticle reference drug products, of which one also has an approved generic drug product (i.e., sodium ferric gluconate (SFG)). These products are indicated for the treatment of iron deficiency anemia and are administered intravenously. On the molecular level, iron nanomedicines are colloids composed of an iron oxide core with a carbohydrate coating. This formulation makes nanomedicines more complex than conventional small molecule drugs. As such, these products are often referred to as nonbiological complex drugs (e.g., by t…
Plasma pharmacokinetics and tissue distribution study of cajaninstilbene acid in rats by liquid chromatography with tandem mass spectrometry
2010
Cajaninstilbene acid (CSA; 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid) is a major active constituent of pigeonpea leaves, has been proven to be effective in clinical treatment of diabetes, hepatitis, measles and dysentery. A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of CSA in rat plasma and various tissues (brain, heart, lung, liver, spleen, small intestine and kidney) of rat for the first time. Rat plasma and tissue distribution pre-treated by protein precipitation with acetoacetate was analyzed using LC-MS/MS with an electrospray ionization (ESI) interface, and isoliquiritigenin was us…
Biopartitioning micellar chromatoraphy to predict blood to lung, blood to liver, blood to fat and blood to skin partition coefficients of drugs
2009
[EN] Biopartitioning micellar chromatography (BMC), a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 in adequate experimental conditions, has demonstrated to be useful in mimicking the drug partitioning process into biological systems. In this paper, the usefulness of BMC for predicting the partition coefficients from blood to lung, blood to liver. blood to fat and blood to skin is demonstrated. PLS2 and multiple linear regression (MLR) models based on BMC retention data are proposed and compared with other ones reported in bibliography. The proposed models present better or similar descriptive and predictive capability. (C) 2008 Elsevier B.V. All rights r…
Use of molecular topology for the prediction of physico-chemical, pharmacokinetic and toxicological properties of a group of antihistaminic drugs
2002
We used molecular connectivity to search mathematical models for predicting physico-chemical (e.g. the partition coefficient, P), pharmacokinetic (e.g. the time of maximum plasma level, and toxicological properties (lethal dose, LD) for a group of antihistaminic drugs. The results obtained clearly reveal the high efficiency of molecular topology for the prediction of these properties. Randomization and cross-validation by use of leave-one-out tests were also performed in order to assess the stability and the prediction ability of the connectivity functions selected.
Opioid analgetics retention–pharmacologic activity models using biopartitioning micellar chromatography
2002
Opioids are drugs used in medicine for pain control. In this paper, retention-pharmacokinetics and retention-pharmacodynamics relationships of opioids are proposed and statistically validated. These models are based on the compound retention in the biopartitioning micellar chromatography system (BMC), a new methodology which has successfully been used to develop QRAR models for many other families of compounds. The obtained results are compared to the traditional QSAR models using lipophilicity data. The adequacy of QRAR models is due to the fact that the characteristics of the compounds such as the hydrophobicity, electronic charge and steric effects determine both their retention in BMC a…
Biowaiver monographs for immediate release solid oral dosage forms: quinidine sulfate.
2009
Literature data are reviewed relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of new multisource and reformulated immediate release (IR) solid oral dosage forms containing quinidine sulfate. Quinidine sulfate's solubility and permeability, its therapeutic use and index, pharmacokinetics, excipient interactions and reported BE/bioavailability (BA) problems were taken into consideration. The available data are not fully conclusive, but do suggest that quinidine sulfate is highly soluble and moderately to highly permeable and would likely be assigned to BCS Class I (or at worst BCS III). In view of the inconclusiveness of the data and, more imp…
Eine Nierenfunktionsanalyse durch die Computertomographie
1992
The CT clearance in a number of urological patients (39 patients, 25 with normal renal function) was studied by means of an "area under curve" (AUC) method, using a region of interest. 31 patients were given meglumine ioxithalamate and 8 patients Iopamidol as a contrast medium. Both for total and partial function there was highly significant correlation with isotope clearance with good reproducibility. The difference in the pharmacokinetics of the contrast media affected the absolute clearance values.