Abstract:
:Various diesters of 9-[(1,3-dihydroxy-2-propoxy)-methyl]guanine (DHPG) were screened in order to identify a derivative with improved oral absorption. The solubilities and dissolution rates decreased with increasing chain length and branching of the ester group. However, the dipropionate ester showed an anomalously faster dissolution rate. The rates of hydrolysis to DHPG in the presence of intestinal homogenates were found to increase with increasing carbon number for the straight-chain alkyl esters and decreased with branching. The shorter-chain alkyl esters were relatively more stable in intestinal homogenates than in liver homogenates. Therefore they may have a better membrane permeability than DHPG due to their intact ester group. The hydrolysis rates in human blood increased with increasing carbon number for the straight-chain alkyl esters. The dipropionate ester appeared to be the most promising derivative because of its rapid dissolution rate, slower hydrolysis in the intestine, and rapid conversion to DHPG in liver and blood.
journal_name
Pharm Resjournal_title
Pharmaceutical researchauthors
Benjamin EJ,Firestone BA,Bergstrom R,Fass M,Massey I,Tsina I,Lin YYdoi
10.1023/a:1016462801968subject
Has Abstractpub_date
1987-04-01 00:00:00pages
120-5issue
2eissn
0724-8741issn
1573-904Xjournal_volume
4pub_type
杂志文章abstract:PURPOSE:Adenoviruses are being developed for diseases of the gastrointestinal tract. Several in vitro assays were used to predict stability of PEGylated adenovirus along the GI tract and determine in vivo gene transfer after oral administration. METHODS:Recombinant adenovirus was modified with monomethoxypoly(ethylene...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1025714412337
更新日期:2003-09-01 00:00:00
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journal_title:Pharmaceutical research
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doi:10.1007/s11095-004-1882-y
更新日期:2005-03-01 00:00:00
abstract:PURPOSE:This study examines methylprednisolone (MPL) effects on the dynamics of hepatic low-density lipoprotein receptor (LDLR) mRNA and plasma lipids associated with increased risks for atherosclerosis. MATERIALS AND METHODS:Normal male Wistar rats were given 50 mg/kg MPL intramuscularly (IM) and sacrificed at variou...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-007-9371-8
更新日期:2008-04-01 00:00:00
abstract:PURPOSE:At elevated temperatures, the rate of drug release and skin permeation from transdermal delivery systems (TDS) may be higher than at a normal skin temperature. The aim of this study was to compare the effect of heat on the transdermal delivery of two model drugs, nicotine and fentanyl, from matrix-type TDSs wit...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-017-2189-0
更新日期:2017-09-01 00:00:00
abstract::Coprecipitates of fluorescein and magnesium hydroxide demonstrate delayed absorption relative to fluorescein solutions when administered to the airways of the isolated perfused rat lung (IPRL). Perfusate concentration vs time profiles showed that dissolution and not epithelial permeability was the rate-controlling fac...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015942013413
更新日期:1988-09-01 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:PURPOSE:The present study evaluates immobilized artificial membrane (IAM) chromatography for predicting drug permeability across the blood-brain barrier (BBB) and outlines the potential and limitations of IAMs as a predictive tool by comparison with conventional methods based on octanol/water partitioning and octadecyl...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011904311149
更新日期:1998-08-01 00:00:00
abstract::Dihydropyridine ⇄ pyridinium salt-based brain-selective delivery systems were synthesized for the progestins, ethisterone, norethindrone, and norgestrel. After initial lipophilicity and in vitro studies indicated the feasibility of applying these compounds to brain-specific delivery, in vivo distribution studies were ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/A:1016359301852
更新日期:1986-10-01 00:00:00
abstract:PURPOSE:β-Hydroxy-β-methylbutyrate (HMB), a nutritional supplement, elicits anabolic activity in muscle. Here we investigated the mechanism of HMB uptake in muscle cells. METHODS:Murine muscle cells (C2C12) and human mammary epithelial cells (MCF7) were used for uptake. As HMB is a monocarboxylate, focus was on monoca...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-019-2626-3
更新日期:2019-04-17 00:00:00
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更新日期:2007-06-01 00:00:00
abstract:PURPOSE:The purpose of this human intestinal perfusion study was to investigate the transport and metabolism of R/S-verapamil in the human jejunum (in vivo). METHODS:A regional single-pass perfusion of the jejunum was performed using a Loc-I-Gut perfusion tube in 12 healthy volunteers. Each perfusion lasted for 200 mi...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011916329863
更新日期:1998-06-01 00:00:00
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journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1007512617139
更新日期:2000-04-01 00:00:00
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journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1026147620304
更新日期:2003-10-01 00:00:00
abstract::For the last 50 years we have known of a broad-spectrum agent tilorone dihydrochloride (Tilorone). This is a small-molecule orally bioavailable drug that was originally discovered in the USA and is currently used clinically as an antiviral in Russia and the Ukraine. Over the years there have been numerous clinical and...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-020-02799-8
更新日期:2020-03-25 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:PURPOSE:Myricetin (MYR) flavonoid is well-recognized for its antioxidant, anti-inflammatory and anti-tumor potential. Introducing nanomedicine was the ultimate resort to solve the imperfections of this nutraceutical, namely solubility, stability and delivery issues. The study, thus, aims at developing inhalable micropa...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-020-02794-z
更新日期:2020-04-14 00:00:00
abstract:PURPOSE:To study the structure and function of the intestinal H+/ peptide transporter PET1, we compared its amino acid sequence with those of related transporters belonging to the oligopeptide transporter family PTR, and with more distant transporter families. METHODS:We have developed a new approach to the sequence a...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1012070726480
更新日期:1997-04-01 00:00:00
abstract:PURPOSE:The described structure pharmacokinetic pharmacodynamic relationships (SPPR) study explored the utilization of tetramethylcyclopropane analogues of valpromide (VPD), or tetramethylcyclopropane carboxamide derivatives of valproic acid (VPA) as new antiepileptics. METHODS:The study was carried out by investigati...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016055517724
更新日期:1996-02-01 00:00:00
abstract:PURPOSE:An ex vivo intact toe model was developed to assess two different applicator designs for iontophoretic delivery of terbinafine into the nail only or the nail and surrounding skin. METHODS:Iontophoretic permeation studies were carried out on intact cadaver toes using nail-only and nail/skin applicators with a c...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-009-9934-y
更新日期:2009-09-01 00:00:00
abstract::Enoximone and piroximone are cardiotonic agents for use in patients with congestive heart failure. Electroanalytical studies revealed that the dihydroimidazolone functionality was oxidizable and that this property can be analytically useful. The compounds undergo a two-electron, irreversible oxidation in neutral to ac...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015811830830
更新日期:1991-07-01 00:00:00
abstract::A quantitative analysis of the dependence of dissolution rate on the relative surface area occupied by two non-interacting drug mixtures from co-compressed slabs is described. The results from the experimental dissolution rates of each component from naproxen/phenytoin co-compressed slabs under laminar flow conditions...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1018979419714
更新日期:1994-10-01 00:00:00
abstract:PURPOSE:To examine the theoretical/practical utility of the liver-to-blood partition coefficient (Kpuu) for predicting drug-drug interactions (DDIs), and compare the Kpuu-approach to the extended clearance concept AUCR-approach. METHODS:The Kpuu relationship was derived from first principles. Theoretical simulations i...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-020-02797-w
更新日期:2020-03-25 00:00:00
abstract:PURPOSE:This study compared gene expression profiles in mouse lungs after administration of the cationic polymers polyethyleneimine (PEI) or chitosan alone or formulated with a luciferase reporter plasmid (PEI-pLuc, chitosan-pLuc). METHODS:The polymers and formulations were administered intratracheally to Balb/c mice ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-006-9563-7
更新日期:2006-03-01 00:00:00
abstract:PURPOSE:Non-small cell lung cancer is the leading cause of cancer related deaths globally. Considering the side effects and diminishing chemosensitivity to chemotherapy, novel treatment approaches are sought. Hence, we aim to develop a liposomal co-delivery system of pDNA expressing shRNA against PFKFB3 (pshPFKFB3) and...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-017-2244-x
更新日期:2017-11-01 00:00:00
abstract:PURPOSE:Knowledge about the uptake mechanism and subsequent intracellular routing of non-viral gene delivery systems is important for the development of more efficient carriers. In this study we compared two established cationic polymers pDMAEMA and PEI with regard to their transfection efficiency and mechanism of cell...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-007-9287-3
更新日期:2007-08-01 00:00:00
abstract:PURPOSE:The aim of the study was to evaluate organogel nanoparticles as a lipophilic vehicle to increase the oral bioavailability of poorly soluble compounds. Efavirenz (EFV), a Biopharmaceutical Classification System (BCS) Class II, was used as drug model. METHODS:Organogel nanoparticles loaded with EFV were formulat...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-020-02808-w
更新日期:2020-05-11 00:00:00
abstract:PURPOSE:To examine the effect of particle size and morphology on aerosol dispersion using jet-milled and spray-dried mannitol particles in narrow size distributions within the respirable range. METHODS:Particle size and morphology were examined by laser diffraction and scanning electron microscopy, respectively. Aeros...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/b:pham.0000033007.27278.60
更新日期:2004-07-01 00:00:00
abstract::Nasal sprays containing different concentrations of the somatostatin analogue octreotide and sodium tauro-24,25-dihydrofusidate (STDHF) as an absorption promoter were evaluated in two consecutive pharmacokinetic studies in healthy volunteers to characterize their bioavailability and local tolerability. The concentrati...
journal_title:Pharmaceutical research
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1023/a:1018927710280
更新日期:1992-01-01 00:00:00
abstract:PURPOSE:To study epidermal and polyethylene membrane penetration and retention of the sunscreen benzophenone-3 (BP) from a range of single solvent vehicles and evaluate solvent effects on permeability parameters. METHODS:The solubility of BP was measured in a number of solvents. Penetration of BP across human epidermi...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011958006973
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:Polyesters with hydrophilic domains, i.e., poly(D,L-lactic-co-glycolic-co-hydroxymethyl glycolic acid) (PLGHMGA) and a multiblock copolymer of poly(ε-caprolactone)-PEG-poly(ε-caprolactone) and poly(L-lactide) ((PC-PEG-PC)-(PL)) are expected to cause less acylation of encapsulated peptides than fully hydrophobic...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-015-1685-3
更新日期:2015-09-01 00:00:00