Renal clearance–lipophilicity relationships of some organic acids in rabbits, rats and mice

Abstract

The effect of lipophilicity on the renal clearance for a group of weak organic acids (benzoic, phenylacetic and hippuric acid derivatives) was studied in rabbits, rats and mice. These compounds are eliminated in the kidney by glomerular filtration and undergo both tubular secretion and tubular reabsorption. For quantification of the effect of lipophilicity, an equation [formula: see text] was employed, where CLR represents renal clearance of the parent drug, ERPF is effective renal plasma flow, D is the partition coefficient of the acids between octanol and water, and a and b are constants. In interspecies comparison, the values of parameters a and b are similar indicating no significant interspecies differences in this route of elimination.