A simple, fast, sensitive and robust LC-MS/MS bioanalytical assay for evaluating 7α-hydroxy-4-cholesten-3-one biomarker in a clinical program. (December 2016)

• Record Type: Journal Article
• Authors: Yuan, Long; Luo, Yi; Kandoussi, Hamza; Ji, Qin C
• Is Part Of: Bioanalysis. Volume 8:Number 23(2016)
• Page Start: 2445
• Page End: 2455
• Publication Date: 2016-12
• Subjects: biomarker -- LC-MS/MS -- surrogate matrix; Drugs -- Analysis -- Periodicals; 615.19005
• DOI: 10.4155/bio-2016-0219
• Languages: English
• ISSNs: 1757-6180

Abstract

Aim: Serum 7α-hydroxy-cholesten-3-one (C4) has been reported as a biomarker to assess CYP7A1 enzyme activity and bile acid synthesis. To support a clinical program, a sensitive and reliable assay without derivatization was required for the analysis of C4 in human serum.Methodology & results: A systematic approach was used to optimize mass spectrometry, LC and sample extraction conditions, therefore, significantly improved assay sensitivity, and achieved the required quantification limit without derivatization. A surrogate matrix approach was used to overcome the interference from endogenous C4. A stable isotope-labeled C4 was used as internal standard. The samples were extracted using a simple protein precipitation method with 2% formic acid in acetonitrile.Conclusion: A simple, fast, sensitive and robust UHPLC-MS/MS method for the quantification of 0.50 ng/ml C4 in 100 µl human serum was developed and fit for purpose validated. The method was successfully applied to the bioanalysis of C4 in a clinical study.