Abstract：
:First-order rate constants (k) were determined for the hydrolysis of ceftazidime in the pH range of 0.5 to 8.5 at 45, 55, and 65 degrees C by a stability-indicating HPLC assay. In the absence of buffer effects, the pH-rate expression was k = kH1f1(aH+) + kH2f2(aH+) + kH3f3(aH+) + kSf3 + kOHf3(aOH-), where KH and KOH are the catalytic rate constants for the activity of hydrogen (aH+) and hydroxyl (aOH-) ions, respectively, and kS is the rate constant for spontaneous hydrolysis. The fractions of ceftazidime in various stages of dissociation (f1, f2, and f3) were calculated from kinetically determined apparent Ka values of 2.03 x 10(-2) and 4.85 x 10(-5). Catalytic constants (kcat) were calculated for formate, acetate, phosphate, and borate buffers, which accelerated hydrolysis. Each of the rate constants (kH1, kH2, kH3, kS, kOH, and kcat) were described as a function of temperature with calculated A and E values in the Arrhenius equation, kT = Ae-E/RT. Ceftazidime hydrolysis rate constants (k) were calculated as a function of pH, temperature, and buffer by combining the pH-rate expression with the buffer contributions calculated from kcat values and the temperature dependencies. These equations and their parameter values successfully calculated 95 of 104 experimentally determined rate constants with errors of < 10%. Maximum stability was observed in the relatively pH-independent region from 4.5 to 6.5. Hydrolysis rate constants at 30 degrees C were predicted and experimentally verified for four ceftazidime solutions, three of which (pH 4.4 acetate buffer and pH 5.5 and 6.5 phosphate buffers) maintained 90% of their initial concentration for approximately 1.5 days.
journal_name
J Pharm Scijournal_title
Journal of pharmaceutical sciencesauthors
Zhou M,Notari REdoi
10.1002/jps.2600840504subject
Has Abstractpub_date
1995-05-01 00:00:00pages
534-8issue
5eissn
0022-3549issn
1520-6017pii
S0022-3549(15)49805-3journal_volume
84pub_type
杂志文章abstract：:Optical coherence tomography (OCT) is a recently developed optical technique that produces depth profiles of three-dimensional objects. It is a nondestructive interferometric method responding to refractive index variation in the sample under study and can reach a penetration depth of a few millimetres. OCT employs ne...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.21844
更新日期：2010-01-01 00:00:00
abstract：:Profiles of the steady-state concentrations of haloperidol (HL) and its major metabolite, reduced haloperidol (RHL), in plasma versus time were determined in 10 Japanese patients whose schizophrenic symptoms were clinically controlled by fixed, oral maintenance doses (4-30 mg/day, three times a day) for greater than 4...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600811010
更新日期：1992-10-01 00:00:00
abstract：:Modifications of antibacterial activity have been demonstrated using combinations of two antibacterials from trimethoprim, sulfonamides (sulfadiazine, sulfamerazine, and silver sulfadiazine), silver nitrate, and dibromopropamidine isethionate, either formulated in a cream base or dissolved in peptone water. The creams...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600800912
更新日期：1991-09-01 00:00:00
abstract：:The chemical shifts of the methyl groups of 2,4-dimethylbenzo[g]quinoline are defined with respect to concentration, showing that the methyl resonances are reversed from their expected positions in concentrations normally used in NMR spectroscopy. The phenomenon is explained in terms of the probably "fixation" of bond...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600660839
更新日期：1977-08-01 00:00:00
abstract：:The absorption of the model drug carbenoxolone was reevaluated using an in situ rat intestinal perfusion technique in which disappearance from the intestinal lumen, binding to the perfused jejunal segment, and appearance in the mesenteric (jejunal) vein were measured. The effect of the degree of ionization on these pr...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600790510
更新日期：1990-05-01 00:00:00
abstract：:To elucidate drug lipophilicity effects on the bioavailability (BA) of drugs from skin after administration by dissolving microneedles, nine compounds with different lipophilicity indexes (log p value) were formulated into two-layered dissolving microneedles and administered percutaneously to rat skin: desmopressin (D...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.22814
更新日期：2012-03-01 00:00:00
abstract：:Simple and sensitive enzyme immunoassays (EIAs), discriminating a new angiotensin-converting enzyme (ACE) inhibitor, cilazapril [9(s) - [1(s)-(ethoxycarbonyl)-3-phenylpropylamino]-octahydro-10-oxo-6H- pyridazo[1,2-a] [1,2]diazepine-1(s)carboxylic acid] and its active metabolite [9(s)-[1(s)-carboxy-3-phenylpropylamino]...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600760308
更新日期：1987-03-01 00:00:00
abstract：:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has received considerable attention as a potential anticancer agent. However, recombinant Apo2L/TRAIL has several limitations, which include a weak pharmacokinetic profile, namely, a short biological half-life and rapid renal clearance, and an inability t...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.22298
更新日期：2011-02-01 00:00:00
abstract：:Meglumine labeled with carbon-14 was administered orally as 14C-meglumine salicylate to rats and dogs to study its distribution and excretion. The compound was incompletely absorbed; that which was absorbed was rapidly excreted in the urine. Peak blood levels were about 5-10 mug/ml in rats and 2-8 mug/ml in dogs. Tiss...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600660124
更新日期：1977-01-01 00:00:00
abstract：:The solubility equation of Yalkowsky was used to estimate the aqueous solubility of 33 barbiturates in the temperature range of 5 to 45 degrees C. The equation was extended by adding a term which accounts for the effect of pH on the solubility of the drug. The extended equation is successful in estimating the aqueous ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600760120
更新日期：1987-01-01 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：:The influence of ferric ions, EDTA, and visible light on the oxidation of methionine and the covalent reducible and nonreducible dimerization in human Insulin-like Growth Factor I (hIGF-I) in aqueous (1 mM) phosphate buffer solution were studied. A reduced factorial experiment with two levels of each factor was used. ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1021/js960484q
更新日期：1997-09-01 00:00:00
abstract：:A method was developed for the baseline separation of common free bile acids by supercritical fluid chromatography. A phenylbonded silica column, with UV detection at 210 nm, and carbon dioxide modified with methanol as the mobile phase were used. The influence of the stationary phase, modifier concentration, temperat...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600820110
更新日期：1993-01-01 00:00:00
abstract：:We investigated the effect of cytochrome P450 (CYP) 2C9 polymorphism on the inhibition of methylhydroxylation activity of tolbutamide, a typical CYP2C9 substrate, by triazole antifungal agents, fluconazole and voriconazole. Although the Michaelis constants (Km), maximal velocities (Vmax), and Vmax/Km values for CYP2C9...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2016.01.007
更新日期：2016-03-01 00:00:00
abstract：:In this work, a novel risk-based methodology for lot release is proposed. Its objective is to assess the risk that a lot declared to have passed truly meets product specifications. The methodology consists of 3 parts: adaptive sample size determination, estimation of the probability that the product was within specifi...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2019.10.011
更新日期：2020-02-01 00:00:00
abstract：:This work involves the study of the solid-phase and solution crystallization behavior of the N-methylephedrine enantiomers. A systematic investigation of the melt phase diagram of the enantiomeric N-methylephedrine system was performed considering polymorphism. Two monotropically related modifications of the enantiome...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2016.08.005
更新日期：2016-11-01 00:00:00
abstract：:Two oral liquid dosage forms of acetazolamide have been developed. Using the solubility profiles, polyethylene glycol 400 (7%, v/v) was used as the solubilizing agent and propylene glycol (53%, v/v) as the cosolvent to keep acetazolamide in solution. Because of the bitter taste of acetazolamide, sweetening agents (sim...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600790919
更新日期：1990-09-01 00:00:00
abstract：:The spherically agglomerated crystals of aminophylline (theophylline-ethylenediamine complex) can be compounded directly into pharmaceutical formulations without further processing, e.g., granulation. Such crystals were prepared by mixing theophylline and ethylenediamine in a partially miscible solvent system, i.e., o...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600731021
更新日期：1984-10-01 00:00:00
abstract：:The pKa values of benzoic acid, p-methylbenzoic, and p-aminobenzoic acid (PABA) were determined by potentiometric titration in mixtures of 0-0.5 volume fractions of various cosolvents and water. The differences between the aqueous and semiaqueous pKa values were similar for the three solutes at a particular cosolvent-...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600750217
更新日期：1986-02-01 00:00:00
abstract：:Isomazole matrix tablet formulations, with various concentrations of hydroxypropyl methylcellulose (HPMC) hydrogel, were prepared and tested for sustained-release activity. Sustained-release activity was determined by administering isomazole test formulations orally to conscious dogs, instrumented with an indwelling l...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600780715
更新日期：1989-07-01 00:00:00
abstract：:The Setschenow constant, K(salt), of a nonelectrolyte in a NaCl solution is shown to be related to the logarithm of its octanol-water partition coefficient, log K(ow), determined by K(salt) = A log K(ow) + B, where K(ow) is the octanol-water partition coefficient of the solute and the coefficients A and B are constant...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/1520-6017(200012)89:12<1620::aid-jps13>3.0
更新日期：2000-12-01 00:00:00
abstract：:Ascorbic acid (100 mg/ml) and sodium bisulfite (0.5 and 20 mg/ml) prevented more than 10% oxidation of apomorphine hydrochloride in water maintained at room temperature over 1-3 days. Refrigeration at 5 degrees prevented oxidation of apomorphine hydrochloride in aqueous solutions for 1 week. Neither ascorbic acid nor ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600690830
更新日期：1980-08-01 00:00:00
abstract：:This study is to prepare and evaluate Pluronics-modified mixed micelle (MM) to deliver polyphenolic myricetin (MYR) across the blood-brain barrier. MYR has been proven to be an effective anticancer agent against glioblastoma cells in our previous studies. However, the poor solubility of MYR limits its access to the br...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2016.01.016
更新日期：2016-04-01 00:00:00
abstract：:The application of drug ion-selective electrodes as sensors for the direct determination of the released drug in a continuous-flow analyzer for automated dissolution studies is described. Flow-through electrodes, selective to chlorpromazine, amitriptyline, propantheline, cimetidine, and ranitidine, have been construct...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600760911
更新日期：1987-09-01 00:00:00
abstract：:There is a growing clinical interest in developing and commercializing pharmaceutical-grade cannabinoid products, containing primarily tetrahydrocannabinol (THC) and cannabidiol (CBD). The oral bioavailability of THC and CBD is very low due to extensive "first-pass" metabolism. A novel oral THC and CBD formulation, PT...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2017.12.020
更新日期：2018-05-01 00:00:00
abstract：:The morphology of spray-dried particles composed of psicose and hydroxypropyl methylcellulose was modified by adding ammonium bicarbonate (ABC) to the solution. The surface structure of the particles was altered by immediate transformation of ABC to gaseous components during the spray drying. As a result, low-density ...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.23899
更新日期：2014-04-01 00:00:00
abstract：:Intranasal delivery of flurazepam, midazolam, and triazolam was studied in a dog model as a possible alternate route of drug administration for treatment of insomnia. Four beagles received each hypnotic by both intranasal and oral routes on two separate occasions. Plasma concentrations for each hypnotic after dosing w...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1002/jps.2600801207
更新日期：1991-12-01 00:00:00
abstract：:The cyclopropyl amine moiety in GSK2879552 (1) degrades hydrolytically in high pH conditions. This degradation pathway was observed during long-term stability studies and impacted the shelf life of the drug product. This article describes the work to identify the degradation impurities, elucidate the degradation mecha...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2019.04.026
更新日期：2019-09-01 00:00:00
abstract：:Organic anion transporting polypeptides (OATP) 1B1 and OATP1B3 are important determinants of transporter-mediated drug-drug interactions (DDIs). Current studies assessed the OATP1B1 and OATP1B3-mediated DDI potential of vemurafenib, a kinase inhibitor drug with high protein binding and low aqueous solubility, using R-...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1016/j.xphs.2020.06.016
更新日期：2021-01-01 00:00:00
abstract：:Protein and peptide antigens frequently are only slightly immunogenic when utilized alone in vaccines. Formulation of these antigens in a carrier vehicle, particularly when an adjuvant is included, often results in markedly enhanced immune responses. Encapsulation of peptide and protein antigens in liposomes generally...
journal_title：Journal of pharmaceutical sciences
pub_type： 杂志文章
doi：10.1021/js9601593
更新日期：1996-12-01 00:00:00
