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N o v e m b e r 2 1 - 2 2 , 2 0 1 8 | M a d r i d , S p a i n
OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
alliedacademies.comYEARS
Analytical Chemistry 2018
Journal of Chemical Technology and Applications
|
Volume 2
ANALYTICAL CHEMISTRY
International Conference on
J Chem Tech App 2018, Volume 2
CHALLENGES AND CONSIDERATIONS FOR QUANTITATIVE ANALYSIS OF
CHOLESTEROL PRECURSORS AND METABOLITES IN HUMAN PLASMA BY
LC-MS/MS METHODOLOGY
Yong-Xi Li
Medpace Bioanalytical Laboratories, USA
C
oncentrations of Cholesterol Precursors and Metabolites in human body are very closely related to human cognitive perfor-
mance and human heart health as well. Many new drugs are developed to improve the rations of among the precursors or
metabolites in human body for human health needs. Because they are so important biomarkers that sensitive and accurate deter-
minations of all concentrations of the precursors and metabolites are critical during the drug developments and studies. For such
purpose, Bio-analytical methods were developed and fully validated following US FDA and European EMA guidance for Cholesterol
three precursors: Lathosterol, Lanosterol and Desmosterol, and four Cholesterol metabolites: 4β-Hydroxycholesterol, 24S-Hdroxy-
cholesterol, 25-Hdroxycholesterol and 27-Hdroxycholesterol by LC-MS/MS methods at our laboratories. Since such marker mole-
cule structures and polarities are very similar or the same with only a double bond position different, the bio-analytical methodology
faced extremely challenge during our method development stage, which include all extraction procedures, HPLC conditions and
Mass Spectrometer parameters. Especially in human plasma samples, Cholesterol is dominate marker that had significant inter-
ference with the analysis. During the method validations, we have considered that the methods need to be conducted from regu-
latory point of view, that is, “method validation for biomarker assays should address the same questions as method validation for
PK assays……” so that the method accuracy, precision and all stabilities were completed for all assessments to meet acceptance
criteria from the regulatory agencies, instead, not reference methods “fit-for-purpose” for diagnostic. In this presentation, all above
scientific challenges and regulatory considerations are introduced and discussed. All methods were successfully applied to our
several clinical studies, and with later on the methods for phytosterol have provided very useful insights for the drug developments.