Abstract：
:The dissolution kinetics of theophylline monohydrate and anhydrous theophylline were investigated with a rotating-disk apparatus in buffer solutions at 298 K under sink conditions. The observed dissolution rate of theophylline monohydrate under various conditions agreed well with predictions based on the Extended Simultaneous Chemical Reaction and Dissolution concept. Below 337 K, anhydrous theophylline is converted to theophylline monohydrate in contact with water. The dissolution profile of anhydrous theophylline can be divided into three phases: a pre-transformation phase: anhydrous theophylline dissolves; the transformation phase, during which its dissolution rate drops to the level of the theophylline monohydrate dissolution rate; and steady state, at which the dissolution rate of anhydrous theophylline equals the dissolution rate of theophylline monohydrate. The presence of theophylline monohydrate crystals at the dissolving surface was confirmed by IR spectroscopy and microscopic observation. The length of the transformation phase, depending on the characteristics of the diffusion boundary layer, varied with the experimental conditions (e.g., pH and rotation speed). It was concluded that during the dissolution process the disk is covered with theophylline monohydrate crystals that precipitate from the supersaturated medium adjacent to the disk surface, and that crystallization of theophylline monohydrate is a precipitation process controlled by hydrodynamic and diffusion parameters.
journal_name
J Pharm Scijournal_title
Journal of pharmaceutical sciencesauthors
de Smidt JH,Fokkens JG,Grijseels H,Crommelin DJdoi
10.1002/jps.2600750515subject
Has Abstractpub_date
1986-05-01 00:00:00pages
497-501issue
5eissn
0022-3549issn
1520-6017pii
S0022-3549(15)47109-6journal_volume
75pub_type
杂志文章abstract：:The viscosity of xanthan gum solutions in the low shear region was investigated with the aid of a Couette instrument. All solutions were highly pseudoplastic . Solutions containing 0.3-0.5% of the gum exhibited a highly ordered phase at very low shear. Viscosity, the degree of pseudoplasticity , and the value of the t...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600730410
更新日期：1984-04-01 00:00:00
abstract：:In this study, we explored the bioavailability in dogs and chemical potency of generic ritonavir and lopinavir/ritonavir tablet products manufactured by various pharmaceutical companies. Chemical potency of the products was examined by HPLC quantitation of ritonavir and lopinavir. Using a dog model, we determined poin...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.21712
更新日期：2010-02-01 00:00:00
abstract：:Live attenuated influenza vaccine (LAIV) is considered one of the most effective vaccines and can be manufactured quickly and inexpensively to counter seasonal or pandemic influenza. Lyophilization is widely used in vaccine production. However, it requires a longer production cycle and large-scale equipment, thus posi...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2019.02.017
更新日期：2019-07-01 00:00:00
abstract：:The stability of highly purified supercoiled plasmid DNA formulated in simple phosphate or Tris-buffered saline solutions has been characterized to establish the overall degradation processes that occur during storage in aqueous solution. Plasmid DNA stability was monitored during accelerated stability studies (at 50 ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/(SICI)1520-6017(200001)89:1<76::AID-JPS8>3
更新日期：2000-01-01 00:00:00
abstract：:A method to determine drugs having a carbothionamido group using an ammonia gas-sensing electrode is described. To obtain analytical accuracy, the effect of factors that influence the potential is also discussed. Ethionamide or prothionamide was refluxed with 20% HCl to give ammonium chloride, hydrogen sulfide, and a ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600720904
更新日期：1983-09-01 00:00:00
abstract：:The dependency of metformin in vivo disposition on the rate and extent of dissolution was studied. The analysis includes the use of fundamental principles of drug input, permeability, and intestinal transit time within the framework of a compartmental absorption transit model to predict key pharmacokinetic (PK) parame...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.23063
更新日期：2012-05-01 00:00:00
abstract：:Interest in the 5-, 6-, and 7-trifluoromethyl-substituted 2,3-bis(4-methoxyphenyl)indoles as potent, orally active anti-inflammatory agents required a method for their determination in serum, urine, and feces to permit studies of their absorption, metabolism, and excretion. A simple, rapid, sensitive, and specific pro...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600651218
更新日期：1976-12-01 00:00:00
abstract：:A specific, sensitive, rapid, and reproducible analytical GLC method for lidocaine in human plasma, including pharmacokinetic parameters, is described. Aminopyrine is the internal standard. The method was used to study pharmacokinetics in four healthy volunteers following the administration of a lidocaine bolus at a d...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600661007
更新日期：1977-10-01 00:00:00
abstract：:Personalized medicine aims to determine the most adequate treatment and dose regimen to obtain the maximum efficacy and minimum side effect by taking into account patients' characteristics. For numerous reasons, one being ethical and methodological hurdles in including specific populations in clinical trials, innovati...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章,评审
doi：10.1016/j.xphs.2017.04.035
更新日期：2017-09-01 00:00:00
abstract：:The organic extract of the whole plant Xanthorhiza simplicissima was found to exhibit good activity against the AIDS-related opportunistic pathogens Candida albicans, Cryptococcus neoformans, and Mycobacterium intracellularae. Bioassay-directed fractionation of the extract led to the isolation of the known alkaloid be...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600830327
更新日期：1994-03-01 00:00:00
abstract：:Understanding the effect of surfactant properties is critical when designing vesicular delivery systems. This review evaluates previous studies to explain the influence of surfactant properties on the behavior of lipid vesicular systems, specifically their size, charge, stability, entrapment efficiency, pharmacokineti...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章,评审
doi：10.1016/j.xphs.2018.01.005
更新日期：2018-05-01 00:00:00
abstract：:A program is described that permits iterative least-squares nonlinear regression fitting of polyexponential curves using the Hewlett Packard HP 41 CV programmable calculator. The program enables the analysis of pharmacokinetic drug level profiles with a high degree of precision. Up to 15 data pairs can be used, and in...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600740510
更新日期：1985-05-01 00:00:00
abstract：:The hydrolysis of acetylcholine and acetylcholine mustard by acetylcholinesterase was compared over a substrate concentration range of 1-10 mM. Reactions were allowed to proceed for 2 min at 25 degrees. Results of these experiments reveal that the substrates have similar affinities for the enzyme, whereas the maximum ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600640839
更新日期：1975-08-01 00:00:00
abstract：:The aim of this study was to prepare and characterize thiolated chitosan (TC) nanoparticles (NPs) of tizanidine HCl (TZ) and to evaluate its transport across monolayer of RPMI 2650 cells (Human nasal septum carcinoma cell line) followed by assessment of their pharmacokinetic and pharmacodynamic attributes, after intra...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.22780
更新日期：2012-02-01 00:00:00
abstract：:A spectrophotofluorometric assay for coralyne sulfoacetate was developed. Caralyne was extracted from serum samples with n-butyl alcohol, and the drug concentrations were determined fluorometrically at 475 nm when the extract was excited at 325 nm. A biphasic serum decay curve for coralyne was observed for both dogs a...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600670942
更新日期：1978-09-01 00:00:00
abstract：:Dolasetron mesilate (Anzemet) ((2 alpha, 6 alpha, 8 alpha, 9a beta)-octahydro-3-oxo-2,6-methano-2H-quinolizin-8-yl-1 H-indole-3-carboxylate monomethane-sulfonate) is a 5-HT3 receptor antagonist, which is in development for the treatment of chemotherapy-induced emesis. The ketone moiety of dolasetron is rapidly reduced...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1021/js960041m
更新日期：1996-07-01 00:00:00
abstract：:Approximately 30% of active pharmaceutical ingredients (APIs) experience agglomeration, granulation, and breakage during agitated drying. Currently, there is no small-scale bench tool to help assess and observe granulation behavior of APIs in the laboratory and subsequently lead to the development of a robust drying m...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.23762
更新日期：2014-01-01 00:00:00
abstract：:Insulin-degrading enzyme (IDE) has been implicated in the intracellular degradation of insulin in insulin target cells. Knowledge of the existence of this enzyme in the intestine will be beneficial to the achievement of clinical oral efficacy of insulin. A comparative study was conducted with rat intestine, human colo...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1021/js960035q
更新日期：1997-01-01 00:00:00
abstract：:Literature data relevant to the decision to waive in vivo bioequivalence testing for the approval of generic immediate release solid oral dosage forms of proguanil hydrochloride are reviewed. To elucidate the Biopharmaceutics Classification System (BCS) classification, experimental solubility and dissolution studies w...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章,评审
doi：10.1016/j.xphs.2018.03.009
更新日期：2018-07-01 00:00:00
abstract：:Transformation of polymorph I of clopidogrel hydrogen sulfate (CHS) to polymorph II of CHS during the crystallization was monitored by using in situ measurement of ultrasonic velocity. Drowning-out crystallization using methanol as a solvent and isopropyl alcohol as nonsolvent was carried out. The polymorphs were iden...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.21313
更新日期：2008-10-01 00:00:00
abstract：:A α-helical GALA peptide (WEAALAEALAEALAEHLAEALAEALEALAA) has been found to possess dual functions: a pH-dependent inducer of endosomal escape, and a ligand that targets lung endothelium. In the present study, the flexibility of GALA was improved by modifying the edge with polyethylene glycol linker, to increase lung-...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2017.04.075
更新日期：2017-09-01 00:00:00
abstract：:The new concept developed in this study is the design of poly(ethylene glycol) (PEG)-coated biodegradable nanoparticles coupled to folic acid to target the folate-binding protein; this molecule is the soluble form of the folate receptor that is overexpressed on the surface of many tumoral cells. For this purpose, a no...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/1520-6017(200011)89:11<1452::aid-jps8>3.0.
更新日期：2000-11-01 00:00:00
abstract：:The distribution of zidovudine (AZT) between plasma, brain extracellular fluid (ECF), and cerebrospinal fluid (CSF) was investigated in a crossover design study (n = 5) in unanesthetized rabbits. Drug was administered by intravenous (iv) and intracerebroventricular (icv) infusions at the same infusion rate (1.5 mg/h.k...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600840717
更新日期：1995-07-01 00:00:00
abstract：:A gas chromatographic-mass spectrometric method was developed for the stereoselective quantification of threo-methylphenidate (MPD) and its metabolite, ritalinic acid (RA), in plasma or urine. The plasma concentrations of (+)-MPD after oral administration of two 10-mg conventional tablets containing racemic MPD.HCl or...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600790602
更新日期：1990-06-01 00:00:00
abstract：:Drug stability studies are expensive and time consuming. Multiple batches are studied to ensure that a product will consistently remain within specifications for its entire expiration dating period. Some of these studies involve the same drug products in similar packages or in multiple strengths. Application of sound ...
journal_title：Journal of pharmaceutical sciences
pub_type： 指南,杂志文章
doi：10.1002/jps.2600841112
更新日期：1995-11-01 00:00:00
abstract：:The increased incidence of human immunodeficiency virus infection in women has identified an urgent need to develop a female-controlled method to prevent acquisition of human immunodeficiency virus and other sexually transmitted diseases. Women would apply the product intravaginally before intercourse. Development of ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.20107
更新日期：2004-08-01 00:00:00
abstract：:We have used rheological and thermal methods to study the colloidal characteristics of a widely used technical latex. The dispersions of poly(methacrylic acid-ethyl acrylate) (Eudragit L100-55) were found to be stabilized by a combination of electrostatic and steric mechanisms termed as electrosteric stabilization. Th...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1021/js9803555
更新日期：1999-04-01 00:00:00
abstract：:Each of three harmala alkaloids, harmine, harmaline, and harmalol, decreased heart rate and increased pulse pressure, peak aortic flow, and myocardial contractile force in intact normotensive anesthetized dogs. Harmine reduced systemic arterial blood pressure and total peripheral vascular resistance; harmaline-evoked ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600660910
更新日期：1977-09-01 00:00:00
abstract：:This in vitro study evaluated the extent of the absorption and metabolism of propranolol in human skin from four sources. Between 10.4 +/- 3.1 and 36.6 +/- 2.6% of the applied dose was absorbed; however, only a small portion (between 4.1 +/- 0.9 and 16.1 +/- 1.3%) of the dose permeated through the skin. Naphthoxyaceti...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600820802
更新日期：1993-08-01 00:00:00
abstract：:Although acute renal failure (ARF) has been an area of extensive research in recent decades, our understanding of ARF is far from complete. Organic cations (OCs) are primarily excreted via vectorial transport by various renal organic cation transporters (OCTs). It is reasonable to assume that ARF may alter the express...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.21442
更新日期：2009-02-01 00:00:00
