Abstract：
:Cyanocobalamin is photolysed in aqueous solution to produce hydroxocobalamin. The kinetics of photolysis has been studied at pH 1-12 using a newly developed spectrophotometric method for the simultaneous determination of the two compounds at 550 and 525 nm or 361 and 351 nm. Cyanocobalamin follows zero-order kinetics at the pH values studied and the rate is catalysed by both hydrogen and hydroxyl ions. The log k-pH profile indicates that cyanocobalamin has maximum stability near pH 7. The cationic species appears to be more susceptible to photolysis than the neutral form. The rate constant for the reaction at pH 1 is 1.32 x 10(-7) mol l-1 min-1 compared with 0.050 x 10(-7) mol l-1 min-1 at pH 7.
journal_name
J Pharm Biomed Analjournal_title
Journal of pharmaceutical and biomedical analysisauthors
Ahmad I,Hussain W,Fareedi AAdoi
10.1016/0731-7085(92)80004-7subject
Has Abstractpub_date
1992-01-01 00:00:00pages
9-15issue
1eissn
0731-7085issn
1873-264Xpii
0731-7085(92)80004-7journal_volume
10pub_type
杂志文章abstract：:To separate proteins solely based on their difference in hydrodynamic volume in size exclusion chromatography (SEC), the ionic strength of the mobile phase has to be increased in order to avoid secondary ionic interactions between proteins and the stationary phase. However, adding salts to the mobile phase can have a ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2016.09.031
更新日期：2017-09-10 00:00:00
abstract：:The Mahuang-Xingren herb-pair (MX), the combination of Herba Ephedrae (Mahuang in Chinese) and Semen Armeniacae Amarum (Xingren in Chinese), is a classical combination used in traditional Chinese Medicine to treat asthma and bronchitis. A simple and reliable ultra-performance liquid chromatography-tandem mass spectrom...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2015.02.004
更新日期：2015-05-10 00:00:00
abstract：:A procedure based on liquid chromatography-mass spectrometry (LC-MS) is described for determination of caffeine, theobromine, theophylline, taurine in different dietary supplements. After addition of tryptophan as internal standard, both solid and liquid specimens were extracted with 4 ml of hexane/isopropanol (9:1). ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2004.11.013
更新日期：2005-03-09 00:00:00
abstract：:A validated stability indicating RP-HPLC assay of doxofylline was developed by separating its related substances and degradants on LichrocartC18 (250 mm × 4.6 mm; 5 μm) column using 10 mM ammonium acetate and acetonitrile as a mobile phase in a gradient mode of elution at a flow rate of 1.0 mL/min at 30 °C. The column...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2013.02.004
更新日期：2013-05-05 00:00:00
abstract：:Cationic Mn porphyrins are among the most potent catalytic antioxidants and/or cellular redox modulators. Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin chloride (MnTE-2-PyPCl(5)) is the Mn porphyrin most studied in vivo and has successfully rescued animal models of a variety of oxidative stress-related diseas...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2012.03.033
更新日期：2013-01-25 00:00:00
abstract：:The response of tumours to adriamycin, and the cardiotoxicity of the drug, may be related to its pharmacokinetics and plasma levels. Rapid and sensitive methods of adriamycin determination in plasma and urine samples are thus needed. A comparative study shows that high-performance liquid chromatography with fluorimetr...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(83)80042-9
更新日期：1983-01-01 00:00:00
abstract：:A tadalafil analogue was detected for the first time during the screening of a health supplement for undeclared sexual enhancement drugs. The compound had been isolated and purified by preparative high-pressure liquid chromatography (HPLC). Its chemical structure was elucidated using high-resolution mass spectrometry ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2015.08.005
更新日期：2016-01-25 00:00:00
abstract：:A very sensitive and convenient nanobiosensor based on fluorescence resonance energy transfer (FRET) was developed for the detection of a 22-mer oligonucleotides sequence in Human Papillomavirus 18 virus (HPV18) gene. For this purpose, water-soluble CdTe quantum dots (QDs) were synthesized and, subsequently, amino-mod...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2017.01.002
更新日期：2017-03-20 00:00:00
abstract：:This research presents the results obtained from analysis by thin layer chromatography (TLC) of some free amino acids from sanguine plasma samples in the different degree progress in maladies: diabetes, renal syndrome and hepatic cirrhosis. The chromatograms were evaluated with a Shimadzu CS-9000 dual-wavelength flyin...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(01)00479-4
更新日期：2001-11-01 00:00:00
abstract：:A series of synthesised tocainide analogues were characterized for their human serum albumin (HSA) binding, using high-performance liquid affinity chromatography (HPLAC) and circular dichroism (CD). The synthesis and physico-chemical characterization of compounds 7a-7d is reported here. For the HPLAC investigation HSA...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2010.03.005
更新日期：2010-10-10 00:00:00
abstract：:Sunitinib is approved for advanced renal cell cancer, imatinib-resistant or -intolerant gastrointestinal stromal tumors and pancreatic neuroendocrine cancers. It is prescribed at a fixed dose but its plasma exposure shows large inter-individual variations. Taking into account the narrow therapeutic window and the posi...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2019.112949
更新日期：2020-02-05 00:00:00
abstract：:A near-infrared reflection spectroscopy (NIRS) method was developed to determine the total content of kavapyrones, kavain and water in dry extracts of Piper methysticum Forst. (kava kava, Piperaceae). Based on the recorded spectra and the reference data, performed by HPLC and Karl Fischer titration, a chemometrical an...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2004.06.030
更新日期：2004-11-19 00:00:00
abstract：:S-Adenosyl-L-methionine (SAM) and its metabolites S-adenosyl-L-homocysteine (SAH) and methyl-thioadenosine (MTA) are endogenous compounds that are heavily involved in a variety of biochemical processes, and have therefore been the target for several assays in body fluids and tissues. Reversed-phase chromatographic beh...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(93)80029-z
更新日期：1993-04-01 00:00:00
abstract：:The characterization and quantification of the metabolites of chiral drugs still remain a great challenge due to the complexity of the metabolites and most of them are not commercially available. In this study, a practical approach based on the combinatory liquid chromatography-mass spectrometric techniques has been p...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.01.045
更新日期：2014-06-01 00:00:00
abstract：:Because of its essential role in SDS-PAGE, sodium dodecylsulphate (SDS) is generally associated with protein denaturation. However, for SDS-PAGE, proteins are linearized in the presence of SDS, following the exposure to high temperatures and reducing agents. In comparison, the conditions employed during a capillary el...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2012.07.033
更新日期：2012-12-01 00:00:00
abstract：:In vitro dissolution/release tests are an important tool in the drug product development phase as well as in its quality control and the regulatory approval process. Mucosal drug delivery systems are aimed to provide both local and systemic drug action via mucosal surfaces of the body and exhibit significant differenc...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章,评审
doi：10.1016/j.jpba.2017.06.072
更新日期：2018-01-05 00:00:00
abstract：:GR117289X, 3-(3-Bromo-2-[2-(1H-tetrazol-5-yl)-phenyl]-bezofuran-5-yl methyl)-2-butyl- 5-chloro-3H-imidazole-4-carboxylic acid, 1, is an angiotensin II receptor antagonist. A sensitive, accurate and precise assay for the determination of 1 in human plasma and validation data is described. The assay consists of a novel ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(94)e0032-v
更新日期：1994-09-01 00:00:00
abstract：:GC-MS is one of the recommended analytical techniques for the identification and confirmation of opiates in urine. A method for the qualitative detection and quantitation of codeine and morphine in urine samples by this technique has been developed. This method is also suitable for the detection of their main metaboli...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(90)80140-k
更新日期：1990-01-01 00:00:00
abstract：:The objective of this study was to investigate the use of transmission hard X-ray nano-computed-tomography (nano-CT) for characterization of the pore structure and drug distribution in poly (lactic-co-glycolic acid) (PLGA) microspheres encapsulating bovine serum albumin and to study the correlation between drug distri...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2015.04.017
更新日期：2015-08-10 00:00:00
abstract：:Homochirality is essential for life. For a long time, it was considered that d-amino acids were excluded from living systems. In the past 30 years, however, d-amino acids have been found in living organisms in the form of free amino acids, peptides and proteins, owing to advances in the analysis of optical isomers of ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章,评审
doi：10.1016/j.jpba.2015.04.029
更新日期：2015-12-10 00:00:00
abstract：:A simple liquid-phase microextraction (LPME) device combined with high-performance liquid chromatography (HPLC) is presented for the simultaneous analysis of local anaesthetics, lidocaine, bupivacaine, and tetracaine, from human urine sample. An organic solvent showed good compatibility with the mobile phase of the HP...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2005.06.023
更新日期：2006-01-23 00:00:00
abstract：:Understanding the origin and fate of organic impurities within the manufacturing process along with a good control strategy is an integral part of the quality control of drug substance. Following the underlying principles of quality by design (QbD), a systematic approach to analytical control of process impurities by ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2010.01.043
更新日期：2010-08-01 00:00:00
abstract：:Three methods are developed for the determination of two multicomponent mixtures containing guaiphenesine (GU) with salbutamol sulfate (SL), methylparaben (MP) and propylparaben (PP) [mixture 1]; and acephylline piperazine (AC) with bromhexine hydrochloride (BX), methylparaben (MP) and propylparaben (PP) [mixture 2]. ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2006.09.020
更新日期：2007-02-19 00:00:00
abstract：:Aminoimidazole-containing compounds have been found to be electroactive and can be detected by amperometric electrochemical detection (ECD) with a high degree of sensitivity. A liquid chromatography (LC) method using ECD was developed for measuring plasma concentrations of the aminoimidazole-containing drug GP531, a p...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(95)01719-4
更新日期：1996-08-01 00:00:00
abstract：:Collision induced dissociation of triple quadrupole mass spectrometer (CID-QqQ) and high-energy collision dissociation (HCD) of Orbitrap were compared for four neuropeptides Y Y1 (NPY Y1) receptor antagonists and showed similar qualitative fragmentation and structural information. Orbitrap high resolution and high mas...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2018.01.013
更新日期：2018-03-20 00:00:00
abstract：:Health benefits of wine, especially with red wine, have been linked to the presence of a wide range of phenolic antioxidants. Thus, the aim of this study was to develop a simple, high performance thin layer chromatographic (HPTLC) method combined with high resolution digital plate images to visually compare multiple w...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.08.031
更新日期：2015-01-01 00:00:00
abstract：:Popularity of natural-based preparations supporting the sexual potency significantly increased in recent years, which also led to the increase of illegal use of phosphodiesterase type 5 inhibitor (PDE-5) in sexual performance enhancement products. In this study, a rapid U-HPLC‒HRMS/MS method has been developed to simu...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2018.11.007
更新日期：2019-02-05 00:00:00
abstract：:The method validation strategy described consists of four components which are the prevalidation, validation proper, study proper and statistical analyses. These components constitute the platform upon which to evaluate the reliability and reproducibility of a bioanalytical method. Consideration has been given to emul...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(91)80159-7
更新日期：1991-01-01 00:00:00
abstract：:A fully automated method is described, which enables the determination of indomethacin in plasma by reversed-phase HPLC following on-line sample enrichment and clean-up on a short pre-column. The plasma sample is introduced directly into the column switching system. The pre-column, filled with a pellicular bonded phas...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(89)80199-2
更新日期：1989-01-01 00:00:00
abstract：:A photodegradation study of aztreonam solutions exposed to UV irradiation showed that the major product of degradation was the anti-isomer together with some unidentified products. This result was similar to that obtained with cefotaxime and it is postulated that this would be generally true of compounds containing an...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(92)80092-2
更新日期：1992-09-01 00:00:00
