Abstract:
PURPOSE:Several phenomena in tablets indicate that an inhomogeneous pore distribution is formed during the compaction process. Examples are lamination and the capping of corners. In order to gain an understanding of the relation between structure and compact properties, analyzing the structure in a location dependent manner would be extremely useful. Our aim was to visualize and to quantitatively analyze the pore distribution in compacts. METHODS:This was done by embedding a cubic (sodium chloride) compact with polymer, allowing the compact to be cut without disrupting the structure. By doing so, it was possible to make scanning electron microscopic images from different angles at different locations in the compact. These images were made binary with a two-means cluster algorithm (Isodata) after which the porosity could be calculated. Counting the number of transitions from the pixels in the pores to the pixels in the sodium chloride particles in two perpendicular directions allows us to construct a measure for the anisotropic connectivity of the particles. RESULTS:The results show an increase in porosity toward the bottom of the compact and showed a preferred orientation of the pores in the direction of compression. CONCLUSIONS:The proposed method is suitable for analyzing the pore distribution quantitatively and for evaluating anisotropy.
journal_name
Pharm Resjournal_title
Pharmaceutical researchauthors
Wu YS,Frijlink HW,van Vliet LJ,Stokroos I,van der Voort Maarschalk Kdoi
10.1007/s11095-005-5280-xsubject
Has Abstractpub_date
2005-08-01 00:00:00pages
1399-405issue
8eissn
0724-8741issn
1573-904Xjournal_volume
22pub_type
杂志文章abstract::The influence of the jejunal bloodflow on the absorption of theophylline was investigated. The bloodflow through a segment under investigation was varied by changing the systemic blood pressure by means of a donor blood infusion into the jugular vein or by an infusion of isoprenaline or levarterenol into a femoral vei...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/A:1016374508542
更新日期:1984-01-01 00:00:00
abstract:PURPOSE:To investigate the potential of a novel lipid carrier, comprising beads of alpha-cyclodextrin and soybean oil, for topical drug delivery. Adapalene was chosen as a model drug to explore the ability of the beads to encapsulate and release a highly lipophilic compound. MATERIALS AND METHODS:Adapalene-loaded bead...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-007-9395-0
更新日期:2008-02-01 00:00:00
abstract::A colorless, parallelepiped crystal of methyl (2R,3S)-N-benzoyl-3-phenylisoserinate belonging to the space group P2(1) with a = 5.414(4), b = 7.813(1), c = 17.802(7) A, beta = 90.87(4) degrees, Z = 2, V = 752.9 A3, Dcalc = 1.32 g cm-3, and mu calc = 1.02 cm-1 was selected and the structure solved using direct methods....
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015863814901
更新日期:1991-07-01 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 physical and release properties of different molecular weight (MW) pH- and temperature-responsive statistical terpolymers and beads of N-isopropylacrylamide (NIPAAm), butylmethacrylate (BMA) and acrylic acid (AA). METHODS:Random terpolymers of varying MW were synthesized with NIPAAm/BMA/AA of feed...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1018813700535
更新日期:1999-06-01 00:00:00
abstract:PURPOSE:Using human lung cancer cells, we evaluated the involvement of plasminogen activator inhibitor-1 (PAI-1) in the anti-invasive action of cannabidiol, a non-psychoactive cannabinoid. METHODS:Invasion was quantified by a modified Boyden chamber assay. PAI-1 protein in cell culture media and PAI-1 mRNA were determ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-010-0219-2
更新日期:2010-10-01 00:00:00
abstract:PURPOSE:Induction of cell-mediated immune (CMI) responses is crucial for vaccine-mediated protection against difficult vaccine targets, e.g., Chlamydia trachomatis (Ct). Adjuvants are included in subunit vaccines to potentiate immune responses, but many marketed adjuvants stimulate predominantly humoral immune response...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-017-2180-9
更新日期:2017-08-01 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:PURPOSE:1. The assessment of the role of hair follicles and sweat glands in skin resistance and percutaneous iontophoretic flux of 9-desglycinamide, 8-arginine vasopressin (DGAVP) by comparing two skin species: human stratum corneum which contained hair follicles, sweat and sebaceous glands, and shed snake skin which l...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016243706415
更新日期:1995-10-01 00:00:00
abstract::A method to provide near-constant sustained release of high molecular weight, water-soluble proteins from polyanhydride microspheres is described. The polyanhydrides used were poly(fatty acid dimer) (PFAD), poly(sebacic acid) (PSA), and their copolymers [P(FAD-SA)]. P(FAD-SA) microspheres containing proteins of differ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1018929531410
更新日期:1993-04-01 00:00:00
abstract::The stability of an antibiotic formulation (clindamycin phosphate in dextrose), which is stable at room temperature, was assessed by nonisothermal kinetic analysis at elevated temperatures. A preliminary study, conducted to establish apparent rate order, verified the appropriateness of a first-order kinetic model. The...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015840320410
更新日期:1991-05-01 00:00:00
abstract:PURPOSE:To examine the iontophoretic delivery of ALA as a function of pH and to determine the principal mechanisms responsible for its electrotransport. METHODS:Anodal iontophoretic transport of ALA was measured as a function of its concentration and pH of the donor solution. Experiments were performed in vitro using ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011050829531
更新日期:2001-03-01 00:00:00
abstract::The influence of varying protein and fat content in milk of New Zealand White rabbits on the milk-to-plasma drug concentration (M/P) ratio of diazepam was studied. At various time points after littering, a bolus dose (1.5 mg/kg) followed by a 26-hr infusion (1.8 mg/h) of diazepam was administered to freely moving rabb...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015809418284
更新日期:1992-10-01 00:00:00
abstract::Human serum albumin (HSA) was encapsulated in a 50:50 copolymer of DL-lactide/glycolide in the form of microspheres. These microspheres were used as a model formulation to study the feasibility of controlling the release of large proteins over a 20- to 30-day period. We show that HSA can be successfully incorporated i...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015948829632
更新日期:1990-11-01 00:00:00
abstract:PURPOSE:We describe the AERX aerosol delivery system, a new, bolus inhalation device that is actuated at preprogrammed values of inspiratory flow rate and inhaled volume. We report on its in vitro characterization using a particular set of conditions used in pharmacokinetic and scintigraphic studies. METHODS:Multiple ...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1012058323754
更新日期:1997-03-01 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
abstract:PURPOSE:To evaluate the reaction of a large series of pharmacologically significant 1,4-dihydropyridine (1,4-DHP) compounds with superoxide (O2.-) in dimethylsulfoxide using differential pulse voltammetry and controlled potential electrolysis. METHODS:Differential pulse voltammetry was used to track the consumption of...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1022291624933
更新日期:2003-02-01 00:00:00
abstract:PURPOSE:An integrated ionic mobility-pore model for epidermal iontophoresis is developed from theoretical considerations using both the free volume and pore restriction forms of the model for a range of solute radii (rj) approaching the pore radii (rp) as well as approximation of the pore restriction form for rj/rp < 0...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011907201096
更新日期:1998-10-01 00:00:00
abstract::Nanoparticles, including lipopolyamines leading to lipoplexes, liposomes, and polyplexes are targeted drug carrier systems in the current search for a successful delivery system for polynucleic acids. This review is focused on the impact of gene and siRNA delivery for studies of efficacy, pharmacodynamics, and pharmac...
journal_title:Pharmaceutical research
pub_type: 杂志文章,评审
doi:10.1007/s11095-008-9646-8
更新日期:2009-01-01 00:00:00
abstract:PURPOSE:The aim of this study was to investigate whether biodegradable nanocapsules could be obtained by the emulsification-diffusion technique. METHODS:This technique consists of emulsifying an organic solution containing an oil, a polymer, and a drug in an aqueous solution of a stabilizing agent. The subsequent addi...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1011934328471
更新日期:1998-07-01 00:00:00
abstract:PURPOSE:The purpose of the present study was to use the human colorectal carcinoma cell line. Caco-2, as a human intestinal epithelial model for studying the effects of cyclodextrins as absorption enhancers. METHODS:Cyclodextrins of varying sizes and physicochemical characters were investigated. The effects of the cyc...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1016225707807
更新日期:1995-09-01 00:00:00
abstract::The transport of thyrotropin releasing hormone (TRH) in rabbit buccal mucosa in vitro has been investigated with respect to (a) rate and type of metabolism of TRH on mucosal and serosal sides of buccal mucosa, (b) mechanism of TRH transport including charge effect on its permeability, and (c) pathway and rate-limiting...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015883217858
更新日期:1992-09-01 00:00:00
abstract::The release of lithium carbonate incorporated into polymethylmethacrylate, polyvinyl chloride, hydrogenated vegetable oil, and carbomer matrix tablets was studied in vitro. The formulation containing 10% carbomer showed a sustained-release profile comparable to that of a standard, commercially available, sustained-rel...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1015863204732
更新日期:1990-04-01 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:There is evidence that cholesterol affects the ATPase and transport functions of P-glycoprotein (P-gp). To study the influence of cholesterol on P-gp in a well defined lipid environment, we reconstituted P-gp in egg phosphatidylcholine (PhC) and PhC/cholesterol proteoliposomes with negligible residual amounts o...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-007-9326-0
更新日期:2007-11-01 00:00:00
abstract:PURPOSE:To analyze the mechanics of some pharmaceutical agglomerates during uniaxial confined compression by using compression parameters derived from the Heckel, Kawakita and Adams equations, and to study the influence of these compression parameters on the tablet-forming ability of agglomerates. METHODS:Force and di...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1007575120817
更新日期:2000-08-01 00:00:00
abstract:PURPOSE:The aim of the study is to determine whether a biodegradable elastomeric device that uses an osmotic pressure delivery mechanism can release different therapeutic proteins at a nearly constant rate in nanomolar concentrations with high bioactivity, given the same formulation conditions. Vascular endothelial gro...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-006-9750-6
更新日期:2006-04-01 00:00:00
abstract:PURPOSE:Pancreatic cancer remains the fourth most common cause of cancer-related death in the United States. Therefore, novel strategies for the prevention and/or treatment are urgently needed. Genistein has been found to be responsible for lowering the rate of pancreatic cancer. However, the molecular mechanisms by wh...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1007/s11095-010-0106-x
更新日期:2010-06-01 00:00:00
abstract::The binding of diflunisal to hydroxypropyl-beta-cyclodextrin (HP beta CD), bovine serum albumin (BSA), human serum albumin (HSA), normal human plasma, and mixed solutions of HP beta CD/protein was studied at 25 degrees C, pH 7.4, by potentiometry using an electrode selective to diflunisal. The experimental data for di...
journal_title:Pharmaceutical research
pub_type: 杂志文章
doi:10.1023/a:1018901912619
更新日期:1994-01-01 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