Abstract：
PURPOSE:The purpose of this study was to investigate the pH-dependent passive and active transport of weakly basic drugs across the human intestinal epithelium. METHODS:The bidirectional pH-dependent transport of weak bases was studied in Caco-2 cell monolayers in the physiologic pH range of the gastrointestinal tract. RESULTS:A net secretion of atenolol and metoprolol was observed when a pH gradient was applied. However, the bidirectional transport of both compounds was equal in the nongradient system. Hence, at lower apical than basolateral pH a change in passive transport caused by an imbalance in the concentration of the uncharged drug species resulted in a "false" asymmetry (efflux ratio). Furthermore, a mixture of pH-dependent passive and active efflux was found for the P-glycoprotein (P-gp, MDR1, ABCB1) substrates, talinolol and quinidine, but not for the neutral drug, digoxin. However, the clinically important digoxin-quinidine interaction depended on the presence of a pH gradient. Hence, the degree of interaction depends on the amount of quinidine available at the binding site of the P-gp. CONCLUSIONS:Active efflux of weak bases can only be accounted for when the fraction of unionized drug species is equal in all compartments because the transport is biased by a pH-dependent passive component. However, this component may take part in vivo and contribute to drug-drug interactions involving P-gp.
journal_name
Pharm Resjournal_title
Pharmaceutical researchauthors
Neuhoff S,Ungell AL,Zamora I,Artursson Pdoi
10.1023/a:1025032511040subject
Has Abstractpub_date
2003-08-01 00:00:00pages
1141-8issue
8eissn
0724-8741issn
1573-904Xjournal_volume
20pub_type
杂志文章abstract：PURPOSE:Cationic liposomes are expected to be useful as nonviral vectors for gene delivery. Cationic liposomes showed cytotoxicity, and we proposed that the cytotoxicity is through apoptosis. In this study, we examined the effects of liposomal properties, such as liposomal charge, size, membrane fluidity, and PEG coati...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1024441702398
更新日期：2003-07-01 00:00:00
abstract：:We describe an assay for acrolein in urine, employing derivatization with m-aminophenol in the presence of ferrous sulfate solution in sulfuric acid. The derivative (7-OH quinoline; DER) and the internal standard (quinine-bisulfate; IS) were separated on a 10-micron particle, 8 mm x 10-cm C18 cartridge in conjunction ...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018964401677
更新日期：1993-11-01 00:00:00
abstract：PURPOSE:The goal of this investigation was to demonstrate whether the intrinsic flux of a drug diffusing across a membrane mounted in a flow-through diffusion cell may be accurately and easily determined by accounting for the accumulation in the receiver chamber. METHODS:Mathematical modeling, applied to transdermal d...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1016216611809
更新日期：1995-12-01 00:00:00
abstract：PURPOSE:Present study assessed the influence of gallate esterification on the anti-cancer activity of procyanidin B2 (B2) in androgen-dependent human prostate carcinoma LNCaP cells employing B2-3,3'-di-O-gallate (B2-G(2)), two mono-gallate esters B2-3-O-gallate (B2-3G) and B2-3'-O-gallate (B2-3'G) and the parent compou...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-009-0037-6
更新日期：2010-04-01 00:00:00
abstract：PURPOSE:To investigate how likely two extended release formulations are to be bioequivalent when they demonstrate f2 similarity. METHOD:Dissolution profiles were simulated using the Weibull model and varying model parameters around those of a reference profile. The f2 values were calculated for the comparisons of each...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-011-0377-x
更新日期：2011-05-01 00:00:00
abstract：:Recently a new in vivo approach in man, using a regional intestinal perfusion technique, has been developed. The perfusion tube consists of a multichannel tube with two inflatable balloons, which are placed 10 cm apart. The tube is introduced orally and the time required for insertion and positioning of the tube is ap...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015888813741
更新日期：1992-10-01 00:00:00
abstract：PURPOSE:We have evaluated a new process, involving solution-enhanced dispersion by supercritical fluids (SEDS), for the production of polymeric microparticles. METHODS:The biodegradable polymers, Poly (DL-lactide-co-glycolide): copolymer composition 50:50 (DL-PLG), Poly (L-lactide) (L-PLA), Poly (DL-lactide) (DL-PLA) ...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018868423309
更新日期：1999-05-01 00:00:00
abstract：:Transdermal drug delivery of ionized drugs can be enhanced by iontophoresis. Drug in the ionic form, contained in some reservoir, can be "phoresed" through the skin with a small current across two electrodes, one above the reservoir and one at a distal skin location. Positive ions can be introduced from the positive p...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/A:1016327822325
更新日期：1986-12-01 00:00:00
abstract：PURPOSE:To study the pulmonary absorption and tolerability of various formulations of the decapeptide cetrorelix acetate in rats by a new aerosol delivery system (ASTA-ADS) for intratracheal application. METHODS:Using the ASTA-ADS, cetrorelix liquid formulations (aqueous solutions for ultrasonic nebulization) were fir...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1011028227155
更新日期：2001-06-01 00:00:00
abstract：:Effects of protease inhibitors and absorption enhancers on the absorption of salmon calcitonin (sCT) were evaluated after intratracheal coadministration to rats using the plasma Ca level as an index. Remarkable absorption enhancement could be attained with unsaturated fatty acids such as oleic acid and polyoxyethylene...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018926007902
更新日期：1994-09-01 00:00:00
abstract：PURPOSE:Chemically modified heparin-DOCA was prepared and found to have markedly lower anticoagulant activity than heparin. In the present study, we elucidated the antiangiogenic and antitumoral activities of heparin-DOCA derivative. METHODS:To evaluate the antiangiogenic and antitumoral effects of heparin-DOCA, capil...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-006-9139-6
更新日期：2007-01-01 00:00:00
abstract：PURPOSE:Covalent binding between N-acetyl-L-cysteine (NAC) and albumin was evaluated kinetically by conducting in vitro experiments. METHOD:After 14C-NAC was incubated with human or rat serum, the solution was analyzed by anion-exchange HPLC. The albumin-bound 14C-NAC was quantified by measuring the radioactivity in t...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1020749211745
更新日期：2002-11-01 00:00:00
abstract：PURPOSE:E-selectin is a cell adhesion molecule that is specifically expressed in the inflammatory vascular endothelium in response to cytokines such as IL-1 beta and TNF-alpha, and interacts with specific ligands containing sialyl Lewis X (Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc-, SLex). In order to investiga...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018849029727
更新日期：1999-02-01 00:00:00
abstract：PURPOSE:To determine the mechanism(s) by which effervescence induces penetration enhancement of a broad range of compounds ranging in size, structure, and other physiocochemical properties across rat and rabbit small intestinal epithelium. METHODS:Effervescent induced penetration enhancement was investigated in vitro ...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1011936901638
更新日期：1998-06-01 00:00:00
abstract：PURPOSE:Nanocrystalline drug-polymer dispersions are of significant interest in pharmaceutical delivery. The purpose of this work is to demonstrate the applicability of methods based on two-dimensional (2D) and multinuclear solid-state NMR (SSNMR) to a novel nanocrystalline pharmaceutical dispersion of ebselen with pol...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-012-0713-9
更新日期：2012-07-01 00:00:00
abstract：PURPOSE:To assess the effects of selective lipid extraction and tape stripping on transepidermal water loss (TEWL) at three body regions in the pig. METHODS:Lipids were extracted from the abdominal, inguinal. and back regions using three different solvent extraction procedures or cellophane tape stripping (15x) on Yor...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1010944529387
更新日期：2001-07-01 00:00:00
abstract：PURPOSE:Lapatinib, a small molecule EGFR/HER2 inhibitor, partially inhibits the outgrowth of HER2+ brain metastases in preclinical models and in a subset of CNS lesions in clinical trials of HER2+ breast cancer. We investigated the ability of lapatinib to reach therapeutic concentrations in the CNS following (14)C-lapa...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-011-0601-8
更新日期：2012-03-01 00:00:00
abstract：PURPOSE:Simple uncoated compressed tablets with a central hole (donut-shape) are proposed to provide a constant drug release over a long period of time (> 20 hrs). The effect of hole size and drug solubility on the release kinetics is investigated. METHODS:The donut-shaped polyethylene oxide (PEO, Mw = 4 x 10(6)) tabl...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1016218716951
更新日期：1995-07-01 00:00:00
abstract：:Various carboxylic acid esters of the N-hydroxymethyl derivative of N-benzyloxycarbonylglycine benzylamide, used as a peptide-like model, were prepared and their decomposition kinetics studied in aqueous solution and in human plasma solutions. These N-acyloxymethylamide derivatives were found to undergo a facile decom...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015839426229
更新日期：1991-10-01 00:00:00
abstract：:The mechanism of release from sustained-release adinazolam mesylate tablets was assessed by the Higuchi equation and by analysis of drug release profiles through 60% released using the Peppas equation. Computed values of the diffusional exponent, n, ranged from 0.59 to 0.66. Values of n in this range are consistent wi...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015834114359
更新日期：1991-12-01 00:00:00
abstract：PURPOSE:To investigate cellular uptake pathways of novel anionic siRNA-lipoplexes as a function of formulation composition. METHODS:Anionic formulations with anionic lipid/Ca(2+)/siRNA ratio of 1.3/2.5/1 (AF1) and 1.3/0.3/1 (AF2) were utilized. Uptake mechanisms were investigated using uptake inhibition and co-localiz...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-012-0952-9
更新日期：2013-04-01 00:00:00
abstract：:Chemical enhancers and vehicles were tested for their ability to improve the percutaneous absorption of leuprolide, a nonapeptide (luteinizing hormone releasing hormone analogue; MW 1209.4). In vitro permeabilities in nude mouse, snake, and cadaver skin were evaluated in either Franz diffusion cells or a Bronaugh flow...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015860324161
更新日期：1992-12-01 00:00:00
abstract：PURPOSE:The preparation of drug/cyclodextrin complexes is a suitable method to improve the dissolution of poor soluble drugs. The efficacy of the Controlled Particle Deposition (CPD) as a new developed method to prepare these complexes in a single stage process using supercritical carbon dioxide is therefore compared w...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-006-9177-0
更新日期：2007-03-01 00:00:00
abstract：:Moisture sorption characteristics and the effect of moisture content on the compression properties of two dextrose-based directly compressible diluents, namely, Emdex (diluent A) and Sweetrex (diluent B) were studied. Both diluents sorbed moisture rapidly at relative humidities greater than 60%. For both the diluents,...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015889414533
更新日期：1991-03-01 00:00:00
abstract：PURPOSE:To characterize the uptake mechanism of zidovudine (AZT), a nucleoside reverse transcriptase inhibitor, in syncytiotrophoblast cells using the TR-TBT 18d-1 cell line previously established by our group. MATERIALS AND METHODS:The effects of several transporter inhibitors on the initial and steady-state apical u...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-008-9564-9
更新日期：2008-07-01 00:00:00
abstract：PURPOSE:Anticancer chemotherapy usually involves the administration of several anticancer drugs that differ in their action mechanisms. Here, we aimed to test whether the combination of omacetaxine mepesuccinate (OMT) and doxorubicin (DOX) could show synergism, and whether the liposomal co-delivery of these two drugs c...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-014-1317-3
更新日期：2014-08-01 00:00:00
abstract：PURPOSE:Predicting human skin permeability of chemical compounds accurately and efficiently is useful for developing dermatological medicines and cosmetics. However, previous work have two problems; 1) quality of databases used, and 2) methods for prediction models. In this paper, we attempt to solve these two problems...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-015-1629-y
更新日期：2015-07-01 00:00:00
abstract：:Silk is a remarkable biopolymer with a long history of medical use. Silk fabrications have a robust track record for load-bearing applications, including surgical threads and meshes, which are clinically approved for use in humans. The progression of top-down and bottom-up engineering approaches using silk as the basi...
journal_title：Pharmaceutical research
pub_type： 杂志文章,评审
doi：10.1007/s11095-018-2534-y
更新日期：2018-11-05 00:00:00
abstract：PURPOSE:This study aims to develop liposomal formulations containing synergistic antibiotics of colistin and ciprofloxacin for the treatment of infections caused by multidrug-resistant Pseudomonas aeruginosa. METHODS:Colistin (Col) and ciprofloxacin (Cip) were co-encapsulated in anionic liposomes by ammonium sulfate g...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-018-2464-8
更新日期：2018-08-09 00:00:00
abstract：PURPOSE:The aim of the present study was to design a new mucosal drug delivery system composed of liposomes dispersed within a bioadhesive hydrogel containing methyl-beta-cyclodextrin (Me(beta)CD) for controlled drug release. METHODS:A hydrophilic model molecule, inulin, was encapsulated within positively charged and ...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-005-4591-2
更新日期：2005-06-01 00:00:00
