LogD denotes the partition co-efficient of drug candidates in a lipophilic phase such as octanol and a hydrophilic phase like water.

The LogD value is valuable to predict many ADME properties such as solubility in buffers and gut, cellular permeability, the ability to penetrate the blood-brain barrier and the uptake into the intestine.

Assay Methodology

Test compounds are mixed with octanol and phosphate buffer. The relative drug concentrations in each phase is determined by LC-MS and the LogD is calculated.