Abstract：
PURPOSE:The purpose of this study was to stabilize the vinca alkaloids, vincristine sulfate (VCR) and vinblastine sulfate (VBL), in poly(lactide-co-glycolide) (PLGA) microspheres and to release the drugs in a sustained manner for more than a month. METHODS:An oil-in-oil emulsion-solvent extraction method was used to encapsulate VCR and VBL in PLGA50/50 microspheres. Stability and release kinetics of the drugs during the incubation at 37 degrees C in PBS/Tween 80 were assessed by HPLC. Degradation products were identified with HPLC-MS. RESULTS:VCR and VBL were encapsulated in PLGA microspheres unchanged. During the microsphere incubation, however, VCR degraded inside the particles with a t1/2 approximately 7.5 days. The degradation product was identified by LC-MS as the deformyl derivative, commonly formed at acidic pH. VBL, which differs only by a stable methyl group in place of the N-formyl group in VCR, was completely stable in the PLGA microclimate. The neutralization of acidic PLGA microclimate by addition of 3-10% Mg(OH)2 completely inhibited deformylation of VCR during release. but introduced a new degradation product formed under the more alkaline conditions used during the preparation. The substitution of Mg(OH)2 with a weaker base, ZnCO3, inhibited the formation of both degradation products resulting in VCR stabilization of >92% for 4 weeks. The optimal formulations of VCR (containing ZnCO3) and VBL (no additives) slowly and continuously released stable drugs for over a month. CONCLUSIONS:VCR and VBL were successfully stabilized and released in a sustained manner from PLGA microspheres. Co-encapsulation of ZnCO3 stabilizes VCR against acid-catalyzed degradation during release from the polymer and minimizes VCR decomposition during encapsulation.
journal_name
Pharm Resjournal_title
Pharmaceutical researchauthors
Marinina J,Shenderova A,Mallery SR,Schwendeman SPdoi
10.1023/a:1007522013835subject
Has Abstractpub_date
2000-06-01 00:00:00pages
677-83issue
6eissn
0724-8741issn
1573-904Xjournal_volume
17pub_type
杂志文章abstract：PURPOSE:Prostaglandin E(1) (PGE(1)) is an effective treatment for peripheral vascular diseases. The encapsulation of PGE(1) in nanoparticles for its sustained-release would improve its therapeutic effect and quality of life (QOL) of patients. METHODS:In order to encapsulate PGE(1) in nanoparticles prepared with a poly...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-009-9891-5
更新日期：2009-07-01 00:00:00
abstract：PURPOSE:This work explores the distribution of water and its effects on molecular mobilities in poly(vinylpyrrolidone) (PVP) glasses using molecular dynamics (MD) simulation technology. METHODS:PVP glasses containing 0.5% and 10% w/w water and a small amount of ammonia and Phe-Asn-Gly were generated. Physical aging pr...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-005-5277-5
更新日期：2005-08-01 00:00:00
abstract：PURPOSE:To gain information on the chemical stability pattern and the kinetics of the degradation of recombinant hirudin variant HV1 (rHir), a thrombin-specific inhibitor protein of 65 amino acids, in aqueous solution as a function of pH. METHODS:Stability of rHir was monitored at 50 degrees C in the framework of a cl...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1011918108849
更新日期：1998-09-01 00:00:00
abstract：PURPOSE:In this work, the alacepril thiolesterase, which catalyzes the hydrolyzing reaction of the thiolester linkage in alacepril and the conversion from alacepril to deacetylalacepril, was purified from rat liver cytosol and characterized. METHODS:A purification procedure for the thiolesterase consisted of ammonium ...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1025073720126
更新日期：2003-08-01 00:00:00
abstract：PURPOSE:Magnetic resonance imaging (MRI) is widely used for diagnostic imaging in preclinical studies and in clinical settings. Considering the intrinsic low sensitivity and poor specificity of standard MRI contrast agents, the enhanced delivery of MRI tracers into tumors is an important challenge to be addressed. This...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-015-1736-9
更新日期：2015-11-01 00:00:00
abstract：PURPOSE:Relatively large (>5 microm) and porous (mass density <0.4 g/cm3) particles present advantages for the delivery of drugs to the lungs, e.g., excellent aerosolization properties. The aim of this study was, first, to formulate such particles with excipients that are either FDA-approved for inhalation or endogenou...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018910200420
更新日期：1999-11-01 00:00:00
abstract：PURPOSE:Since a previous qualitative study carried out by us showed the existence of an important influence of the particle size on the percolation thresholds and taking into account that the existing theoretical models can only provide qualitative explanation to this influence, the purpose of this work is to carry out...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1016088424993
更新日期：1996-03-01 00:00:00
abstract：PURPOSE:The purpose of this study was to evaluate glucose responsiveness in HepG2 human hepatoma cells transduced by a recombinant adeno-associated virus (rAAV) vector containing the insulin gene promoter. and to investigate the effect of protamine sulfate on rAAV-mediated gene delivery. METHODS:Recombinant AAV vector...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1010923924844
更新日期：2001-07-01 00:00:00
abstract：PURPOSE:Studies were conducted to evaluate whether the use of an in vitro model of the blood-brain barrier (BBB) resulted in more accurate predictions of the in vivo transport of compounds compared to the use of a human intestinal cell line (Caco-2). METHODS:The in vitro BBB model employs bovine brain capillary endoth...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1016462205267
更新日期：2002-07-01 00:00:00
abstract：PURPOSE:The purpose of this study was to characterize the amorphous state of ursodeoxycholic acid (UDCA) samples by using isothermal microcalorimetry, X-ray diffraction, infrared (IR) spectroscopy and solid state carbon 13 nuclear magnetic resonance (13C-NMR) spectroscopy, and to demonstrate the application of the ther...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1012114825513
更新日期：1997-06-01 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 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：: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:To evaluate the effect of the size of low molecular weight hyaluronan (LMW-HA) oligomers on the targeting ability of the HA-containing copolymers to the CD44-overexpressing cells for delivering Paclitaxel (PTX) to ovarian cancer. METHODS:LMW-HA oligosaccharides of 4, 6, 8, 10, 12 and 14 sugar residues were att...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-012-0672-1
更新日期：2012-04-01 00:00:00
abstract：PURPOSE:The purpose of the study was to examine the suitability of using laser diffraction to measure the fine particle fraction (FPF) of drugs emitted from carrier-free dry powder aerosol formulations. MATERIALS AND METHODS:Particle size distribution of terbutaline sulphate from Bricanyl Turbohaler, which contained l...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-006-9056-8
更新日期：2006-09-01 00:00:00
abstract：PURPOSE:The purpose of this study was to determine the potential effect of probenecid on the pharmacokinetics of zalcitabine in HIV-positive patients. METHODS:Twelve patients received single oral 1.5 mg doses of zalcitabine alone and during probenecid treatment (500 mg at 8 and 2 hours before and 4 hours after zalcita...
journal_title：Pharmaceutical research
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1023/a:1016009029536
更新日期：1996-03-01 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：:A novel application of attenuated total reflectance IR spectroscopy (ATR-IR) was used to monitor the outer several microns of the stratum corneum (SC) and, thereby, demonstrate enhanced percutaneous absorption in vivo in man. 4-Cyanophenol (CP) as a model permeant yielded a unique IR signal, distinct from those of the...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015960815578
更新日期：1990-08-01 00:00:00
abstract：PURPOSE:To describe a computational tool to calculate molecular descriptors of potential application in ADME virtual screening of antitumor Pt(II) drug candidates. METHODS:The multistep computational procedure consists in (a) building and optimization (PM3) of the 3D structures of the investigated complexes, (b) param...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-010-0317-1
更新日期：2011-03-01 00:00:00
abstract：PURPOSE:To identify the mechanism behind the unexpected bio-performance of two amorphous solid dispersions: BMS-A/PVP-VA and BMS-A/HPMC-AS. METHODS:Solubility of crystalline BMS-A in PVP-VA and HPMC-AS was measured by DSC. Drug-polymer interaction parameters were obtained by Flory-Huggins model fitting. Drug dissoluti...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-012-0695-7
更新日期：2012-10-01 00:00:00
abstract：PURPOSE:To investigate the potential of chitosan nanoparticles as a system for improving the systemic absorption of insulin following nasal instillation. METHODS:Insulin-loaded chitosan nanoparticles were prepared by ionotropic gelation of chitosan with tripolyphosphate anions. They were characterized for their size a...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018908705446
更新日期：1999-10-01 00:00:00
abstract：:The binding of 1-anilino-8-naphthalenesulfonate (ANS) to bovine serum albumin (BSA), human serum albumin (HSA), and human plasma has been studied by potentiometric titration utilizing a laboratory constructed ion selective electrode (ISE) of ANS. Three classes of ANS binding sites were found on BSA, HSA, and plasma at...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015855613083
更新日期：1991-07-01 00:00:00
abstract：:An on-line simultaneous assay for the enantiomers of verapamil (VA) and its three metabolites in plasma was developed with column-switching HPLC. This system consists of an ovomucoid protein chiral stationary phase coupled to an achiral reversed-phase column via a dilution tube and a trapping column. The reversed-phas...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1015848806240
更新日期：1991-08-01 00:00:00
abstract：PURPOSE:Basal insulins with improved kinetic properties can potentially be produced using acylation by fatty acids that enable soluble, high-molecular weight complexes to form post-injection. A series of insulins, acylated at B29 with fatty acids via glutamic acid spacers, were examined to deduce the structural require...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-012-0739-z
更新日期：2012-08-01 00:00:00
abstract：PURPOSE:The pharmacokinetics of corticosteroids in pregnancy were analyzed to assess maternal/fetal disposition and factors controlling fetal exposure. Area/Moment equations and compartmental models for estimating pharmacokinetic parameters from single dose data during pregnancy were developed. METHODS:Betamethasone i...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-004-7681-7
更新日期：2004-12-01 00:00:00
abstract：:The dermal route is an attractive route for vaccine delivery due to the easy skin accessibility and a dense network of immune cells in the skin. The development of microneedles is crucial to take advantage of the skin immunization and simultaneously to overcome problems related to vaccination by conventional needles (...
journal_title：Pharmaceutical research
pub_type： 杂志文章,评审
doi：10.1007/s11095-017-2223-2
更新日期：2017-11-01 00:00:00
abstract：PURPOSE:To develop a semi-physiological-based model describing simultaneously the time course of immature and mature B-lymphocytes after topotecan (TPT) administration to tumor-bearing rats. METHODS:Twenty-four tumor-bearing BDIX male rats received a single 6 mg/kg intra-peritoneal dose of TPT or saline. Mature and im...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1007/s11095-009-0025-x
更新日期：2010-03-01 00:00:00
abstract：PURPOSE:It is reported that the cerebrospinal fluid (CSF) to plasma unbound concentration ratio of fleroxacin at steady-state is approximately 0.5 in experimental animals. These results can be accounted for by assuming the presence of an active transport system for the efflux of this compound across the choroid plexus....
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1016081618149
更新日期：1996-04-01 00:00:00
abstract：PURPOSE:To study the expression of P-glycoprotein (P-gp), lung resistance-related protein (LRP), and caveolin-1 (cav-1) in the human bronchial epithelial cell line 16HBE14o-. METHODS:The presence of P-gp, LRP, and cav-1 in 16HBE14o- cell layers was evaluated using immunocytochemical staining and visualization with con...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1023230328687
更新日期：2003-04-01 00:00:00
abstract：:Turbidimetric or light scattering assays can be used to determine the extent of aggregation in protein formulations. Using low molecular weight urokinase (LMW-UK) as a model protein, the effect of polymeric additives on heat-induced aggregation was evaluated. Previous work has shown that under 60 degrees C heat treatm...
journal_title：Pharmaceutical research
pub_type： 杂志文章
doi：10.1023/a:1018935420680
更新日期：1994-07-01 00:00:00
