Search results for "Concentration."
showing 10 items of 1849 documents
Identification of chemosensitizers by drug repurposing to enhance the efficacy of cancer therapy
2020
Abstract The progressively rising drug resistance has driven the development of chemosensitizers, which aim to enhance the current chemotherapeutic efficacy through either quantitatively increasing intracellular drug concentration by inhibiting drug efflux, vesicle sequestration, and metabolic inactivation or qualitatively exerting concomitant effects on cellular regulation to promote apoptosis. Given the high failure rates and costs during standard drug development, drug repurposing represents an effective and economic approach for chemosensitizer identification. By applying drug repurposing, a wide range of existing clinic drugs including anticardiovascular agents, immunosuppressants, ant…
The Biopharmaceutics Classification System: Subclasses for in vivo predictive dissolution (IPD) methodology and IVIVC
2013
The Biopharmaceutics Classification System (BCS) has found widespread utility in drug discovery, product development and drug product regulatory sciences. The classification scheme captures the two most significant factors influencing oral drug absorption; solubility and intestinal permeability and it has proven to be a very useful and a widely accepted starting point for drug product development and drug product regulation. The mechanistic base of the BCS approach has, no doubt, contributed to its wide spread acceptance and utility. Nevertheless, underneath the simplicity of BCS are many detailed complexities, both in vitro and in vivo which must be evaluated and investigated for any given…
Unraveling the behavior of oral drug products inside the human gastrointestinal tract using the aspiration technique: History, methodology and applic…
2020
Fluid sampling from the gastrointestinal (GI) tract has been applied as a valuable tool to gain more insight into the fluids present in the human GI tract and to explore the dynamic interplay of drug release, dissolution, precipitation and absorption after drug product administration to healthy subjects. In the last twenty years, collaborative initiatives have led to a plethora of clinical aspiration studies that aimed to unravel the luminal drug behavior of an orally administered drug product. The obtained drug concentration-time profiles from different segments in the GI tract were a valuable source of information to optimize and/or validate predictive in vitro and in silico tools, freque…
Subcutaneous Injection of Drugs: Literature Review of Factors Influencing Pain Sensation at the Injection Site.
2019
The subcutaneous administration route is widely used to administer different types of drugs given its high bioavailability and rapid onset of action. However, the sensation of pain at the injection site might reduce patient adherence. Apart from a direct effect of the drug itself, several factors can influence the sensation of pain: needle features, injection site, volume injected, injection speed, osmolality, viscosity and pH of formulation, as well as the kind of excipients employed, including buffers and preservatives. Short and thin needles, conveniently lubricated and with sharp tips, are generally used to minimize pain, although the anatomic injection site (abdomen versus thigh) also …
Monitoring of Plasma Concentrations of Psychotropic Drugs in Pharmacovigilance
2015
The primary aims of pharmacovigilance are supervision and prevention of medication-related problems under everyday conditions. Pharmacovigilance is an indication for monitoring plasma concentrations, i.e. conducting therapeutic drug monitoring (TDM). Using TDM, it can be clarified if observed unwanted drug effects may be attributed to abnormally high or low drug concentrations. Utmost benefits from TDM are obtained for pharmacovigilance when the method is adequately integrated into the clinical treatment process. How to do this is described in consensus guidelines for TDM in psychiatry. During the last 20 years, TDM was very successful for detection of multiple pharmacokinetic drug-drug int…
SPCCTDM, a Catalogue for Analysis of Therapeutic Drug Monitoring Related Contents in the Drug Prescription Information
2010
Therapeutic drug monitoring (TDM) has consistently been shown to be useful for optimization of drug therapy. For the first time, a method has been developed for the text analysis of TDM in SPCs in that a catalogue SPC-ContentTDM (SPCCTDM) provides a codification of the content of TDM in SPCs. It consists of six structure-related items (dose, adverse drug reactions, drug interactions, overdose, pregnancy/breast feeding, and pharmacokinetics) according to implicit or explicit references to TDM in paragraphs of the SPC, and four theory-guided items according to the information about ranges of plasma concentrations and a recommendation of TDM in the SPC. The catalogue is regarded as valid for t…
Photophysical Properties of Charged Cyclometalated Ir(III) Complexes: A Joint Theoretical and Experimental Study
2011
The photophysical properties of a series of charged biscyclometalated [Ir(ppy)(2)(N boolean AND N)](1+) complexes, where ppyH is 2-phenylpyridine and N boolean AND N is 2,2'-bipyridine (bpy), 6-phenyl-2,2'-bipyridine (pbpy), and 6,6'-dipheny1-2,2'-bipyridine (dpbpy) for complexes 1, 2, and 3, respectively, have been investigated in detail. The photoluminescence performance in solution decreases from 1 to 3 upon attachment of phenyl groups to the ancillary ligand. The absorption spectra recorded over time suggest that complex 3 is less stable compared to complexes 1 and 2 likely due to a nucleophilic-assisted ancillary ligand-exchange reaction. To clarify this behavior, the temperature depen…
Automated analysis of images for molecular quantification in immunohistochemistry.
2018
The quantification of the expression of different molecules is a key question in both basic and applied sciences. While protein quantification through molecular techniques leads to the loss of spatial information and resolution, immunohistochemistry is usually associated with time-consuming image analysis and human bias. In addition, the scarce automatic software analysis is often proprietary and expensive and relies on a fixed threshold binarization. Here we describe and share a set of macros ready for automated fluorescence analysis of large batches of fixed tissue samples using FIJI/ImageJ. The quantification of the molecules of interest are based on an automatic threshold analysis of im…
Mechanism of the Citrate Transporters in Carbohydrate and Citrate Cometabolism in Lactococcus and Leuconostoc Species
1998
ABSTRACT Citrate metabolism in the lactic acid bacterium Leuconostoc mesenteroides generates an electrochemical proton gradient across the membrane by a secondary mechanism (C. Marty-Teysset, C. Posthuma, J. S. Lolkema, P. Schmitt, C. Divies, and W. N. Konings, J. Bacteriol. 178:2178–2185, 1996). Reports on the energetics of citrate metabolism in the related organism Lactococcus lactis are contradictory, and this study was performed to clarify this issue. Cloning of the membrane potential-generating citrate transporter (CitP) of Leuconostoc mesenteroides revealed an amino acid sequence that is almost identical to the known sequence of the CitP of Lactococcus lactis . The cloned gene was exp…
Environmental Isocyanate-Induced Asthma: Morphologic and Pathogenetic Aspects of an Increasing Occupational Disease
2011
Occupational diseases affect more and more people every year. According to the International Labour Organization (ILO), in 2000 an estimated amount of at least 160 million people became ill as a result of occupational-related hazards or injuries. Globally, occupational deaths, diseases and injuries account for an estimated loss of 4% of the Gross Domestic Product. Important substances that are related to occupational diseases are isocyanates and their products. These substances, which are used in a lot of different industrial processes, are not only toxic and irritant, but also allergenic. Although the exposure to higher concentrations could be monitored and restricted by technical means, v…