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Biomedical subjects

E L Inman

Publications and source records attributed to E L Inman.

4 recordsLinked to original sources

Determination of EDTA in vancomycin by liquid chromatography with absorbance ratioing for peak identification.

An LC method is described for the determination of EDTA in vancomycin formulations. EDTA is complexed with iron and the Fe(EDTA)- complex is separated from vancomycin components on a reversed-phase column using an ion pair mobile phase. Quantitation is achieved using UV detection, with absorbance ratioing employed to discriminate between the analyte and vancomycin-related compounds. The complexity of the sample matrix and the trace levels of EDTA that are of interest dictate unique development considerations. This method offers good specificity and precision over the range 20-300 ppm EDTA in vancomycin formulations, while maintaining a degree of simplicity. Wavelength selection is optimized to demonstrate the potential application of absorbance ratioing to trace determinations. This method has been effectively applied to vancomycin formulations containing a wide range of chemical impurities and is not affected by vancomycin degradation products.

Chromatography, High Pressure Liquid

Determination of vancomycin related substances by gradient high-performance liquid chromatography.

A gradient high-performance liquid chromatographic method for the determination of vancomycin related substances is described. This method was developed to profile vancomycin, co-fermentation products, and degradation products. The resultant chromatograms confirm the multifactored nature of vancomycin, separating a number of peaks from the main component. The development of acceptable chromatographic performance is described, with the final method intended for use as a control assay. Quantitation of total related substances is made by comparing the relative area of the main peak to total peak area in a pair of chromatograms from a stock solution and a twenty-five fold dilution. A rapid-scan UV detector was used to demonstrate the similar spectral characteristics of the vancomycin related substances, confirming the validity of the relative area approach. Statistical method validation data are included, evaluating the use of this method for quantitative applications. Example applications demonstrate the effectiveness of this method.

Chromatography, High Pressure Liquid

General method validation guidelines for pharmaceutical samples.

Method validation guidelines, which provide an organizational structure for the design and evaluation of a validation procedure, are presented for a wide range of pharmaceutical applications. The validation guidelines are based on the analyte concentration/sample matrix combination to which the method will be applied. These guidelines include the selection of appropriate validation parameters, design considerations for evaluation, and a discussion of acceptance guidelines for the determination of acceptable method performance. A set of tables is included which illustrates the selection and testing procedure and tailors the entire validation process to the specific characteristics of the determination to be made.

Chemistry, Pharmaceutical