New ADME e-book is out: Permeability and transporters

12 October 2018

We are excited to release yet another e-book: Permeability and transporters. This e-book marks the fifth and final publication in the originally planned series.

Passive permeability and active drug transport are key factors determining how a drug is absorbed, distributed and eliminated, and thus investigation of these characteristics is an integral part of drug discovery and development. This e-book focuses on how passive permeation and active transport affect the pharmacokinetics of drug molecules and how to study these phenomena.

As this fifth e-book completes our ADME e-book series which was started in April 2017, we would like to thank you readers for your interest and support. You can download all our e-books on our website via this link. Have a good read!

Simultaneous quantitation of cholesterol metabolites using LC/HR-MS

Our scientists have developed a method for simultaneous quantitation of cholesterol metabolites 4α- and 4β‑hydroxycholesterol from human plasma utilising ultrahigh performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC/HR-MS). This sensitive and validated method has a considerably higher throughput than the traditional LC/MS/MS method which requires laborious sample derivatisation to produce adequate analytical sensitivity.

4β‑hydroxycholesterol may possibly be used as an endogenous biomarker of CYP3A4 enzyme activity. The isomer, 4α‑hydroxycholesterol can be used as an indicator of proper handling of samples as the plasma and serum levels of 4α‑hydroxycholesterol increase during uncontrolled storage conditions.

For further details, read the article about the method published in the Journal of Chromatography B.