2010 Partition coefficient-LogD

adme-T applica Tion noTepar TiTion coefficienTlog dThe partition coefficient between water or buffer and n-octanol or cyclohexane is the most widely used measure of chemical compound lipophilicity. Lipophilicity is a major structural factor governing both pharmacokinetics and pharmacodynamics of drugs.Cerep has developed high-throughput microassays for the determination of this important physicochemical parameter. Log D pH 7.40oct, Log D , pH 7.40cyc❚ Definition of partition coefficientThe partition coefficient of a chemical compound provides a thermodynamic measure of its hydrophilicity-lipophilicity balance. in the laboratory, a small amount of compound is added to a system of two essentially immiscible liquids consisting of an aqueous phase (water or buffer) and an organic phase. once the compound has fully equilibrated with the two solvents, the partition coefficient can be calculated by dividing the amount of compound present in the organic phase by the amount of compound present in the aqueous phase and applying the logarithm. for example, if the amount of a compound in the organic phase were tenfold higher than in the aqueous phase, the partition coefficient would be 1. This example assumes that there are equal volumes of both phases.❚ What significance Does the tition coefficient ve for Drug Dy?modern screening technology and the recent combinatorial Lipophilicity is a key factor determining in vivo behavior of drugstrend to more lipophilic ...