Abstract:
:Determination of the kinetics of water-soluble degradation products inside poly(lactide-co-glycolide) (PLGA) delivery systems during polymer degradation is important to evaluate the polymer microclimate conditions, particularly microclimate pH changes for optimization of encapsulated drug stability. A pre-derivatization high-performance liquid chromatography (HPLC) method was developed for separation and quantification of water-soluble acid impurities and degradation products in PLGA. Thin PLGA films (approximately 200 microm) were incubated in PBS/0.02% Tween 80, pH 7.4, for 6 weeks. Water-soluble monomers and oligomers were obtained from polymer films after repeated CHCl(3)/H(2)O extraction and then derivatized into bromophenacyl esters. With the common chromophore, the esters were separated and quantified by HPLC with increased ultraviolet (UV) sensitivity at 254 nm. The total amount of water-soluble acids in the extract was validated by potentiometric titration with tetrabutyl ammonium hydroxide. During the first 3 weeks of incubation of PLGA 50:50 (inherent viscosity = 0.63 dL/g), the principal water-soluble acids in the polymer were glycolic, lactic, and lactoyllactic acids, and an unknown oligomer. After 4 weeks of incubation, a large fraction of higher molecular weight oligomers was observed. Pre-derivatization HPLC can be used to accurately measure water-soluble acid distribution, and may be invaluable to examine the degradation behavior of PLGAs, including the underlying mechanism of polymer microclimate pH development.
journal_name
J Pharm Scijournal_title
Journal of pharmaceutical sciencesauthors
Ding AG,Schwendeman SPdoi
10.1002/jps.10524subject
Has Abstractpub_date
2004-02-01 00:00:00pages
322-31issue
2eissn
0022-3549issn
1520-6017pii
S0022-3549(16)31408-3journal_volume
93pub_type
杂志文章abstract::The pharmacokinetics of aniracetam (AP), a new cognitive performance enhancer, and its main metabolites was investigated after intravenous (iv) and oral administrations to rat. The plasma levels of AP, 4-p-anisamidobutyric acid (ABA), and p-anisic acid (AA) were determined simultaneously by the HPLC method. The plasma...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1021/js970355p
更新日期:1998-05-01 00:00:00
abstract::Hydroxypropyl cellulose films were prepared by compression molding of three different lots of hydroxypropyl cellulose powder at 149 degrees C, 188 degrees C, and 232 degrees C. Rectangular pieces were cut from these films and viscosity average molecular weight (Mv), degree of orientation, and rate of dissolution were ...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600740509
更新日期:1985-05-01 00:00:00
abstract::A high-performance liquid chromatographic (HPLC) assay to quantitate methylparaben in urine was developed. Standard curves were linear and recovery of the paraben from urine averaged 82.6%. The urinary excretion of methylparaben in six preterm infants (less than or equal to 31 weeks gestational age), who were receivin...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600720919
更新日期:1983-09-01 00:00:00
abstract::Econazole is a feasible alternative treatment in the management of fungal keratitis. Nevertheless, its low water solubility is considered the main limitation to the incorporation into ophthalmic formulations. In this work, econazole nitrate is solubilized by using cyclodextrins to achieve an optimum therapeutic concen...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1016/j.xphs.2017.12.028
更新日期:2018-05-01 00:00:00
abstract::The role of particle size and surface modification on biodistribution of nanocarriers is widely reported. We report for the first time the role of nanoparticle shape on biodistribution. Our study demonstrates that irregular shaped polymer lipid nanoparticles (LIPOMER) evade kupffer cells and localize in the spleen. We...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.22052
更新日期:2010-06-01 00:00:00
abstract::Water evaporation rates were measured from thin samples of a model layered structure of stratum corneum lipids with 32% water. A model with only free fatty acids present gave the lowest evaporation rates, while a model with only oleic acid gave values approximately 50% higher. Using the total lipid spectrum of stratum...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600780808
更新日期:1989-08-01 00:00:00
abstract::We describe the key issues and possibilities for continuous final dosage formation, otherwise known as downstream processing or drug product manufacturing. A distinction is made between heterogeneous processing and homogeneous processing, the latter of which is expected to add more value to continuous manufacturing. W...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章,评审
doi:10.1002/jps.24247
更新日期:2015-03-01 00:00:00
abstract::Cyclosporin A (CyA) is a good candidate for incorporation in colloidal carriers such as nanoparticles (NP) that would diminish the adverse effects associated with its use under conventional pharmaceutical dosage forms and improve bioavailability after oral administration. In this study a composite rotational experimen...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1021/js950164r
更新日期:1996-02-01 00:00:00
abstract::A round-robin study compared four methods of residual ethylene oxide analysis. Results from the six participating laboratories, along with a statistical treatment of the data, are presented. ...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600640837
更新日期:1975-08-01 00:00:00
abstract::A GLC method for determining theophylline, hydroxyethyltheophylline, and diphenylpyraline hydrochloride is presented. The method permits the separation and quantitative determination of the therapeutically active ingredients with a single injection in an overall time of approximately 2.5 hr. ...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600680438
更新日期:1979-04-01 00:00:00
abstract::The binding of acetazolamide to human erythrocytes was studied in vitro. Blood and plasma samples were analyzed by electron-capture GLC. At 37 degrees, drug equilibrated between plasma and erythrocytes in approximately 40 min. The effect of plasma concentration on the steady-state level of drug within the erythrocytes...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600660532
更新日期:1977-05-01 00:00:00
abstract::Cosalane is a potent inhibitor of HIV replication with multiple sites of action. The purposes of this study were to (a) determine the extent and nature of cosalane binding to mucin, alpha(1)-acid glycoprotein (AAG), plasma, and human (HSA) and bovine serum (BSA) albumin, and (b) determine the primary site(s) of cosala...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/1520-6017(200105)90:5<659::aid-jps1022>3.0
更新日期:2001-05-01 00:00:00
abstract::Water/n-octanol partition coefficients (log P) for 33 1,2-dithiole-3-thiones and for 18 1,2-dithiol-3-ones were determined by RP-HPLC measurement of the concentration of the solute in aqueous solution after equilibrium. Depending on the nature of the substituents (alkyl or aryl) and their position(s) (4,5, or both) on...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600840914
更新日期:1995-09-01 00:00:00
abstract::Simultaneously Manufactured Nano-In-Micro (SIMANIM) particles for the pulmonary delivery of antibodies have been prepared by the spray-drying of a double-emulsion containing human IgG (as a model antibody), lactose, poly(lactide-co-glycolide) (PLGA) and dipalmitoylphosphatidylcholine (DPPC). The one-step drying proces...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.21673
更新日期:2009-11-01 00:00:00
abstract::Targeted echogenic liposome dispersions for ultrasonic enhancement of vasoactive and pathological components of endothelium and atherosclerosis have recently been developed. The component lipids required for acoustic and targeting properties include phosphatidylcholine, phosphatidylethanolamine phosphatidylglycerol (P...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.1142
更新日期:2001-12-01 00:00:00
abstract::A quantitative high-pressure liquid chromatographic method, using a reversed-phase column coupled to a fluorescence detector, was developed to determine salicylic acid in bulk aspirin and plain and buffered aspirin tablets. The aspirin was dissolved, filtered, and injected into the chromatograph; the fluorescence of t...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600690518
更新日期:1980-05-01 00:00:00
abstract::Disintegration performance was measured by analysing both water ingress and tablet swelling of pure microcrystalline cellulose (MCC) and in mixture with croscarmellose sodium using terahertz pulsed imaging (TPI). Tablets made from pure MCC with porosities of 10% and 15% showed similar swelling and transport kinetics: ...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.24544
更新日期:2015-10-01 00:00:00
abstract::A hollow cylinder intravitreal implant was developed to achieve sustained release of protein to the retina for the treatment of retinal diseases. Hollow cylinders were fabricated by molding and cross-linking hyaluronic acid, the major component of the vitreous humor. Hollow cylinders were filled with a concentrated pr...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1016/j.xphs.2018.04.024
更新日期:2018-09-01 00:00:00
abstract::A stereoselective and sensitive method for the determination of nilvadipine, a new dihydropyridine calcium antagonist, in human plasma was developed. An internal standard, the deuterated analogue of racemic nilvadipine, was added to the plasma and extracted with an n-hexane:ethyl acetate (92.5:7.5) mixture under alkal...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600760410
更新日期:1987-04-01 00:00:00
abstract::An automated, stability-indicating, UV spectrophotometric assay for cefazolin is presented. The method employs a reaction with hydroxylamine and derives its stability-indicating power through comparison of reacted and unreacted aliquots of the sample. A double-probe sampling procedure is used. Good agreement with micr...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600640725
更新日期:1975-07-01 00:00:00
abstract::Characterizing and quantifying subvisible particles in protein drug products is critical to ensuring product quality. A variety of analytical methods are used to detect and make meaningful measurements of subvisible particles. Resonant mass measurement (RMM) is a novel technology that characterizes the subvisible part...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1016/j.xphs.2018.12.017
更新日期:2019-05-01 00:00:00
abstract::Three polymorphs (forms I-III), a monohydrate (form S2), and three new solvates [4:1 hydrate (form S1), monohydrate (form S3), and methanol half-solvate (form S4)] were isolated and characterized by X-ray powder diffractometry (XRPD), IR spectroscopy, differential scanning calorimetry (DSC), hot stage microscopy, solu...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600841007
更新日期:1995-10-01 00:00:00
abstract::The crystal structure of the common therapeutic agent, the pentahydrated sodium salt of L-thyroxine hormone (3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]-L-alanine), has been determined and discussed in relation to the drug's stability. The stoichiometry and absolute configuration (-)-C(8)S-[C15H10I4NO4]-.Na+....
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.20155
更新日期:2004-12-01 00:00:00
abstract::Insoluble (visible) aggregates of a homodimer fusion glycoprotein, consisting of the first extracellular domain of a human protein, fused to the hinge, C(H)2, and C(H)3 domains of a human immunoglobulin G(1) (IgG(1)), were observed during early formulation development. The soluble fraction of the fusion protein was co...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.20423
更新日期:2005-09-01 00:00:00
abstract::Reactive high gravity controlled precipitation (HGCP) was carried out to produce salbutamol sulphate (SS) particles suitable for inhalation. Aqueous solutions of free salbutamol base and sulphuric acid were mixed intensely inside a HGCP reactor to form the particles. Spray drying was employed to obtain dry powders. Ph...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.21026
更新日期:2008-02-01 00:00:00
abstract::Alzheimer's disease (AD) is historically difficult to treat, in part because of the inaccessible nature of brain pathology. Amyloid beta and tau proteins drive pathology by forming toxic oligomers that eventually deposit as insoluble amyloid plaques and neurofibrillary tangles. Recent clinical studies suggest that eff...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1016/j.xphs.2019.10.024
更新日期:2020-01-01 00:00:00
abstract::Pharmacokinetic profiles of pentylenetetrazol in the dog were studied following rapid intravenous and oral administrations of a convulsant dose (15-20 mg/kg). Plasma level-time curves after a rapid intravenous injection showed biexponential decline, indicating that the disposition of this drug in the dog follows a two...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600650720
更新日期:1976-07-01 00:00:00
abstract::Hemoglobin microcapsules were prepared through cross-linking of hemoglobin itself with various acyldichlorides. Variations in the reticulation conditions were preformed in order to ameliorate the oxygen dissociation curve, the mean diameter, and the possibility for the microcapsules to be lyophilized. With terephthalo...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.2600710710
更新日期:1982-07-01 00:00:00
abstract::AZD1175 and AZD2207 are 2 highly lipophilic compounds with a significant risk of not achieving therapeutic plasma concentrations due to solubility-limited absorption. The compounds have the same molecular weight and minimal structural differences. The aim of the present work was to investigate whether salts could be a...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.xphs.2016.07.016
更新日期:2016-11-01 00:00:00
abstract::The intrinsic absorption of salbutamol in different intestinal segments of the rat was measured and related with the corresponding intestinal P-glycoprotein (P-gp) expression levels. The apparent absorption rate constants (k(a), h(-1)) observed in each fraction by means of the "in situ" rat gut absorption method after...
journal_title:Journal of pharmaceutical sciences
pub_type: 杂志文章
doi:10.1002/jps.20071
更新日期:2004-06-01 00:00:00