Abstract:
PURPOSE:The purpose of this study is to investigate the characteristics of pGlu-L-Dopa-Pro as a prodrug of L-Dopa. METHODS:pGlu-L-Dopa-Pro and L-Dopa-Pro were synthesized using the standard procedures of peptide synthesis. The conversion of pGlu-L-Dopa-Pro to L-Dopa was studied using pyroglutamyl aminopeptidase I and prolidase. With rats as the animal model, the stability of pGlu-L-Dopa-Pro in intestinal homogenates was determined, then the transport characteristics of pGlu-L-Dopa-Pro were studied using in-situ perfusion and Ussing chambers. RESULTS:pGlu-L-Dopa-Pro, relatively stable in intestinal homogenates and intestinal fluid, had a dimensionless permeability of 1.8 at 0.04 mM. Its intestinal permeability was significantly inhibited by 20 mM captopril, by a mixture of dipeptides, 80 mM Gly-Gly and 5 mM Gly-Pro, and by 2 mM cephradine. Further, in Ussing chambers, its mucosal to serosal permeability decreased dramatically with concentration. Conversion studies showed that pGlu-L-Dopa-Pro was degraded by pyroglutamyl aminopeptidase I, an enzyme releasing the N-terminal pyroglutamic acid, with Vmax and Km of 0.6 mumole/min/g protein and 21 mM, respectively, and that L-Dopa-Pro was degraded by prolidase with Vmax and Km of 44 mumole/min/g protein and 0.48 mM, respectively. CONCLUSIONS:This tripeptide, a potential prodrug of L-Dopa, is absorbed by the intestinal peptide transporter, is relatively stable in the gut wall, and is converted to L-Dopa by peptidases with the cleavage by pyroglutamyl aminopeptidase I to L-Dopa-Pro as the rate limiting step.
journal_name
Pharm Resjournal_title
Pharmaceutical researchauthors
Bai JPdoi
10.1023/a:1016239321494subject
Has Abstractpub_date
1995-07-01 00:00:00pages
1101-4issue
7eissn
0724-8741issn
1573-904Xjournal_volume
12pub_type
杂志文章abstract:PURPOSE:Because interleukin-10 (IL-10) seems a promising new antifibrotic drug, we investigated the pharmacokinetic and biodistribution profile of this potent therapeutic cytokine in rats with extensive liver fibrosis (BDL-3). IL-10 receptor expression was also determined in relation to these aspects. METHODS:To study...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/b:pham.0000048199.94510.b0
更新日期:2004-11-01 00:00:00
abstract::Semitelechelic poly[N-(2-hydroxypropyl)methacrylamide]s (ST-PHPMA) containing one amino end-group and differing in molecular weight were synthesized by radical polymerization in the presence of 2-aminoethanethiol (AET) as chain transfer agent. These polymers were covalently attached via amide bonds to the surface of n...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016247206531
更新日期:1995-05-01 00:00:00
abstract:PURPOSE:To investigate plasmid DNA interactions with liposomes prepared from dimyristoylglyceroethylphosphocholine (EDMPC) and DOPE using high sensitivity differential scanning calorimetry (HSDSC). MATERIALS AND METHODS:Large unilamellar liposomes of EDMPC with DOPE (mol ratio 0-50%) were prepared. Plasmid DNA was add...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-007-9325-1
更新日期:2007-10-01 00:00:00
abstract:PURPOSE:To evaluate the use of an in vitro intestinal permeability model to predict rat and human absorption as well as to evaluate the use of an internal standard to control for intra- and inter-rat variability. METHODS:In vivo peroral absorption and in vitro steady-state intestinal permeability coefficients were det...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1012148300807
更新日期:1997-12-01 00:00:00
abstract:PURPOSE:It was the purpose of this study to develop a new oral drug delivery system for low molecular weight heparin (LMWH) providing an improved bioavailability and a prolonged therapeutic effect. METHODS:The permeation enhancing polycarbophil-cysteine conjugate (PCP-Cys) used in this study displayed 111.4 +/- 6.4 mi...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1023803706746
更新日期:2003-06-01 00:00:00
abstract:PURPOSE:To study the influence of cytotoxicity of macromolecules, VEGF gene expression, and vascular permeability on the enhanced permeability and retention (EPR) effect. METHODS:Mice bearing xenografts of A2780 multidrug resistant human ovarian carcinoma were treated by free doxorubicin (DOX) and N-(2-hydroxypropyl)m...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1007500412442
更新日期:2000-05-01 00:00:00
abstract:PURPOSE:To design and synthesize fatty acid-RGD peptide amphiphiles with ADA linker for their potential delivery of hydrophobic drugs like paclitaxel targeted to α(v)β(3) integrin overexpressing tumors. METHODS:Four amphiphiles - C16 or C18 fatty acid-RGD peptide and ADA linker were designed and synthesized. CMC, size...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-012-0830-5
更新日期:2012-12-01 00:00:00
abstract:PURPOSE:Bioadhesion is an important property of biological membranes, that can be utilized in pharmaceutical and biomedical applications. In this study, we have fabricated mucoadhesive drug releasing films with bio-based, non-toxic and biodegradable polymers that do not require chemical modifications. METHODS:Nanofibr...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-018-2428-z
更新日期:2018-05-22 00:00:00
abstract:PURPOSE:To characterize the distribution of water among various components in a powder blend using solid-state NMR spectroscopy. METHODS:Water sorption behavior of theophylline anhydrate and excipients was determined by dynamic vapor sorption (DVS) and Karl Fischer Titration (KFT) after storing them in humidity chambe...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-016-1972-7
更新日期:2016-10-01 00:00:00
abstract:PURPOSE:Evaluate the ability of (-)-6-aminocarbovir ((-)-6AC) to improve the CNS exposure to (-)-carbovir ((-)-CBV). METHODS:Activation of (-)-6AC in vitro was assessed by incubations of rat brain tissue homogenates. The in vivo brain exposure to (-)-CBV was then examined in rats after iv infusions of either (-)-CBV (...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016229624703
更新日期:1995-06-01 00:00:00
abstract:PURPOSE:The development of a physiologically based absorption model for orally administered drugs in rats is described. METHODS:Unlike other models that use a multicompartmental approach, the GI tract is modeled as a continuous tube with spatially varying properties. The mass transport through the intestinal lumen is ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/b:pham.0000003373.72652.c0
更新日期:2003-11-01 00:00:00
abstract:PURPOSE:Interleukin-10 (IL-10) is an anti-inflammatory molecule that has achieved interest as a therapeutic for neuropathic pain. In this work, the potential of plasmid DNA-encoding IL-10 (pDNA-IL-10) slowly released from biodegradable microparticles to provide long-term pain relief in an animal model of neuropathic pa...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-010-0077-y
更新日期:2010-05-01 00:00:00
abstract:PURPOSE:A patient was denoted to be generic brittle (GB) if they had a negative opinion about generics (e.g. prior history of a switch problem) or took the innovator brand of their most problematic anti-epileptic drug (AED) when generic was available. The aim of this hypothesis-generating study was to assess possible g...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-020-2781-6
更新日期:2020-02-26 00:00:00
abstract:PURPOSE:Herein we report the discovery of a group of derivatized alpha-amino acids that increase the oral bioavailability of sodium cromolyn. METHODS:We prepared three N-acylated alpha-amino acids and used these compounds to demonstrate the oral delivery of cromolyn in an in vivo rat model. In vitro experiments, inclu...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016034913181
更新日期:1996-02-01 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:This study was conducted to investigate the cause of incomplete protein release from photopolymerized poly(ethylene glycol) (PEG) hydrogels and verify the protein-protection mechanism provided by iminodiacetic acid (IDA). METHODS:The in vitro release of bovine serum albumin (BSA) from PEG hydrogels prepared un...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-005-9395-x
更新日期:2006-03-01 00:00:00
abstract:PURPOSE:The encapsulation of pancreatic β-cells in biocompatible matrix has generated great interest in diabetes treatment. Our work has shown improved microcapsules when incorporating the bile acid ursodeoxycholic acid (UDCA), in terms of morphology and cell viability although cell survival remained low. Thus, the stu...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-016-1863-y
更新日期:2016-05-01 00:00:00
abstract:PURPOSE:The lack of effective delivery vehicles impedes in vivo applications of siRNA. The trimethyl chitosan-cysteine (TC) nanoparticles (NPs) were developed for in vivo delivery of tumor necrosis factor α (TNF-α) siRNA via oral gavage and intraperitoneal injection. METHODS:The nanoparticles formulated from TC conjug...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-013-1086-4
更新日期:2013-10-01 00:00:00
abstract:PURPOSE:Recombinant human serum albumin (rHSA), secreted by a Pichia pastoris expression system, was purified by a fast and efficient method, the essential feature of which is strong but reversible binding of the protein to Blue Sepharose. The structural characteristics, stability, and ligand-binding properties of the ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1013391001141
更新日期:2001-12-01 00:00:00
abstract:PURPOSE:The purpose of this study was to use a replicate designed trial to assess the overall, intra- and inter-subject variabilities in pharmacokinetic parameters of CGP 33101 after oral administration of tablets relative to that of powder suspended in water, and to determine the relative proportion of the intra-subje...
journal_title:Pharmaceutical research
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1023/a:1016275402723
更新日期:1995-12-01 00:00:00
abstract::Published permeability coefficient (Kp) data for the transport of a large group of compounds through mammalian epidermis were analyzed by a simple model based upon permeant size [molecular volume (MV) or molecular weight (MW)] and octanol/water partition coefficient (Koct). The analysis presented is a facile means to ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015810312465
更新日期:1992-05-01 00:00:00
abstract::Azo polymers based upon 2-hydroxyethyl methacrylate, methyl methacrylate, and methacrylic acid, and containing N,N'-bis [(methacryloyloxyethyl)oxy(carbonylamino)]azobenzene as azo aromatic agent were evaluated in vivo as coating for colon-specific drug delivery. The gastrointestinal absorption of theophylline from cap...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016283027139
更新日期:1995-02-01 00:00:00
abstract:PURPOSE:We prepared injectable microspheres for controlled release of TAK-029, a water-soluble GPIIb/IIIa antagonist and discussed the characteristics of controlled release from microspheres. METHODS:Copoly(dl-lactic/glycolic)acid (PLGA) microspheres were used for controlled release of TAK-029 [4-(4-amidinobenzoylglyc...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1012190304074
更新日期:1997-09-01 00:00:00
abstract:PURPOSE:The prognosis for glioma patients is poor, and development of new treatments is critical. Previously, we engineered polymer-based vaccines that control GM-CSF, CpG-oligonucleotide, and tumor-lysate presentation to regulate immune cell trafficking and activation, which promoted potent immune responses against pe...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-010-0361-x
更新日期:2011-05-01 00:00:00
abstract::The conditions under which the absorption enhancer palmitoyl L-carnitine chloride (PCC) improved the bioavailability of the poorly absorbed antibiotic cefoxitin throughout the rat intestine has been studied. Cefoxitin alone was appreciably absorbed only in the duodenum (31% vs less than 7% elsewhere). PCC solutions (3...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1018977021183
更新日期:1992-02-01 00:00:00
abstract:PURPOSE:To study the reaction of artelinic acid with chemical model systems of cytochrome P-450 as a means of obtaining authentic samples of the putative metabolites necessary for identification of the mammalian metabolites of artelinic acid. METHODS:Artelinic acid was reacted with different organic complexes of iron(...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1012185124972
更新日期:1997-10-01 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 characterize the pharmacokinetic/pharmacodynamic (PK/PD) properties of a new polyethylene glycol (PEG) conjugate formulation of interferon (IFN)-beta la following subcutaneous (SC) administration in monkeys. METHODS:Single SC injections of 0.3, 1, and 3 million international units (MIU)/kg of PEG-IFN-beta 1...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-004-9009-z
更新日期:2005-01-01 00:00:00
abstract::Microbial metabolism studies of the antimalarial drug arteether (1) have shown that arteether is metabolized by a number of microorganisms. Large-scale fermentation with Aspergillus niger (ATCC 10549) and Nocardia corallina (ATCC 19070) have resulted in the isolation of four microbial metabolites which have been chara...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015845306124
更新日期:1990-02-01 00:00:00
abstract:PURPOSE:Our previous studies showed that the mRNA level of human organic anion transporter (hOAT) 3 in the kidney was correlated with the rate of elimination of an anionic antibiotic cefazolin. However, the correlation coefficient was not so high. In the present study, therefore, we enrolled more patients to examine wh...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-005-8383-5
更新日期:2005-12-01 00:00:00