摘要:

Validation of analytical methodologies is an important aspect of their development/utilization and is widely required in support of industrial product development and registration. In this manuscript, ruggedness as a validation parameter is considered in terms of its definition, appropriate evaluation procedures and acceptance criteria. Additionally, the re-validation of analytical methods is discussed, strategies for the effective development and utilization of system suitability tests are described and the term “stability indiating” is defined.

ISSN:1082-6076    

DOI:10.1080/10826079608014012

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Five isocratic liquid chromatography (LC) methods have been examined for the separation of amoxicillin and its related substances on C18or C8columns. The United States Pharmacopeia (USP) assay method gave better selectivity. Similar selectivity was obtained not only on C18columns but also on C8and poly(styrene-divinylbenzene) columns. The good selectivity was confirmed by a second laboratory. A resolution test using cefadroxil was developed for the method performance. Based on the USP method, a gradient LC method was developed for the analysis of related substances in amoxicillin. This method has been proposed for the assay and purity control in the amoxicillin monographs of the European Pharmacopoeia and will be further examined in a collaborative study.

ISSN:1082-6076    

DOI:10.1080/10826079608014013

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple and rapid capillary electrophoretic method was developed for the simultaneous determination of honokiol and magnolol inMagnolia officinalisextracts and dextrorphan was used as the internal standard. The running buffer was composed of 22.5 mM Na2HPO4and 10 mM Na2B4O7(pH 9.1–9.2). The linear calibration range was 2 – 20 μg/mL for honokiol and 5–50 μg/mL for magnolol. It was found that 0.95 ±0.02 mg of honokiol and 4.37 ± 0.08 mg of magnolol were contained in the ethanol (50%) extracts of 1 g ofMagnolia officinalis. The contents of these two active principles inMagnolia officinaliswas successfully determined within 12 min.

ISSN:1082-6076    

DOI:10.1080/10826079608014014

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An HPLC method for the determination of 2,4-D in tomatoes has been studied. Tomato samples were extracted with acetone-dichloromethane (2:1) after hydrolysis. The extract was cleaned up with acid-base partition and furthermore eluting through XAD-2 column. Then, it was analyzed using reverse phase HPLC. Four different mobile phase mixtures, at two different flow rates of 1.0 and 1.5 mL/min, were tried, to choose the best conditions in the final HPLC determination step. The best results were obtained using the mixture of acetonitrile:water, containing2%of acetic acid (50:50, v/v), at a flow rate of 1.0 mL/min for the separation of 2,4-D standard solutions, but the baseline separation of 2,4-D in the final solution of sample extract could not be achieved due to interferences causing poor resolution as well as low recovery.

ISSN:1082-6076    

DOI:10.1080/10826079608014015

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The simultaneous liquid chromatographic determination of the enantiomers of both fluoxetine and its metabolite norfluoxetine in plasma samples of treated patients is described. The compounds are subjected to solid phase extraction before chromatography. The separation of the analytes is achieved using two chiralcel ODR columns on-line coupled and a mobile phase consisting of acetonitrile-NaClO40.3M (66/34 v/v, pH 2.5) at a flow rate of 0.6 mL/min. The compounds were detected by ultraviolet absorbance at 220 nm. The limit of quantification for each compound was 10ng/mL.

ISSN:1082-6076    

DOI:10.1080/10826079608014016

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Cartridges for Solid-Phase Extraction operating in mixed mode were filled with two phases: C18bonded silica and propylsulfonic acid bonded silica, mechanically blended according to two methods: one dry, the other by suspension in acetonitrile. They were compared with cartridges containing the individual phases, and with a mixed phase having two functionalities bonded onto a common silica particle. The percent recoveries of neutral, basic and acidic environmental pollutants and their reproducibilities were determined by HPLC. After evaluation of the optimum eluent volume, the blended phase prepared without solvent and very rapidly, was overall very promising in terms of retention, reproducibility and composition potential.

ISSN:1082-6076    

DOI:10.1080/10826079608014017

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An RP-HPLC procedure was developed for determining the lipophilicity of a series of isoxazolyl-naphthoquinones which possess antibacterial, trypanosidal and antineoplasic activity. The experimental results were compared with theoretical log P values, and it was found that there was a good relationship between the two methods, except for very lipophilic compounds.

ISSN:1082-6076    

DOI:10.1080/10826079608014018

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An HPLC procedure for the determination of theophyl lline in pharmaceutical preparations is described. A Spherisorb octadecyl-silane ODS-2 C18analytical column and spectrophotometric detection at 273 nm were used. Adequate retention was achieved with a mobile phase containing 0.05 M sodium dodecylsulphate (SDS) and 3% propanol at pH 7. The reproducibilities were 1.2 % and 1.7%for 3.8 and 7.6 μg/mL theophylline concentrations, respectively.

ISSN:1082-6076    

DOI:10.1080/10826079608014019

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper deals with the effect of chromatographic conditions, such as the columns with different batches and lengths, buffer concentration in eluents, gradient profiles, pH-values of buffer and flowrates of the elution, on the retention indices of forensically relevant substances in reversed phase HPLC. Our study shows that retention index is only a method of linear correction. When the retention times of the analytes change, under deviation of chromatographic conditions, proportionally to that of the scale substances, the retention indices can well balance the variation from retention times.

ISSN:1082-6076    

DOI:10.1080/10826079608014020

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Computer simulation software for solvent strength optimization and statistical mixture design based on the solvent | selectivity triangle were useful tools employed for the development of a reversed-phase HPLC method to separate duloxetine, a new anti-depressant compound, and structurally-related impurities. Solvent strength optimization was used to show that adequate separation for all impurities could not be obtained with a single organic modifier and to aid in choosing appropriate boundary conditions for a mixture design study. The mixture design was used to obtain resolution maps for organic modifier mixtures consisting of acetonitrile, methanol, and tetrahydrofuran. Overlapping resolution maps for the peak pairs of interest revealed the solvent composition that would provide the maximum resolution. Finally, solvent strength was optimized at the best solvent composition and information about method robustness obtained.

ISSN:1082-6076    

DOI:10.1080/10826079608014021

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor