Drug Development

Studies from M.A. Kall and co-researchers in the area of chromatography published

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"The analytes were detected by a SCIEX API 4000 triple quadropole instrument using turbo electrospray ionization and multiple reaction monitoring negative mode. The method was validated over the concentration range of 0.5-100 ng/mL. The intra-day precision of the assay, as measured by the coefficient of variation (CV%), was within 4%. The intra-day assay accuracy was found to be within 2.2% of the nominal concentration for all the standards. The average recovery of gaboxadol was about 87% and the ion suppression was approximately 8%. To eliminate late eluters including the glucuronides, a 'front cut' column switching procedure was added to the chromatographic system. The effectiveness of the column switching in eliminating the absolute matrix effect caused by late eluters was demonstrated by the low variation (CV <3.5%) in the peak areas of the internal standard during the assessment of the inter-day precision and accuracy and no significant relative matrix effect was observed as illustrated by the excellent intra-day precision (CV <1.5%) from the assessment of standard samples prepared in five different lots of control plasma. The described bioanalytical method has been successfully utilized for the analysis of gaboxadol in post-dose samples (>8000) from various clinical studies. Inter-day precision and accuracy were assessed from the daily mean (n=2) of QC values from 52 runs, i.e. more than 3000 samples. The inter-day precision of the assay, based on the coefficient of variation of QC, ranged from 2.1 to 5.1%," wrote M.A. Kall and colleagues, .

The researchers concluded: "The inter-day assay accuracy was found to be within 4% of the nominal concentration for all QC samples."

Kall and colleagues published their study in the Journal of Chromatography B (Development and validation of a selective and sensitive bioanalytical procedure for the quantitative determination of gaboxadol in human plasma employing mixed mode solid phase extraction and hydrophilic interaction liquid chromatography with tandem mass spectroscopic detection. Journal of Chromatography B, 2007;858(1-2):168-76).

For additional information, contact M.A. Kall, Drug Development ADME, Dept. of Early Development Pharmacokinetics, H Lundbeck, A, S Ottiliavej 7-9, DK-2500 Valby-Copenhagen, Denmark.

The publisher's contact information for the Journal of Chromatography B is: Elsevier Science BV, PO Box 211, 1000 AE Amsterdam, Netherlands.

Keywords: Denmark, Chromatography, Diagnosis, Diagnostics.

This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2007, Life Science Weekly via NewsRx.com.