A novel model for prediction of human drug clearance by allometric scaling.
Sixty-one sets of clearance (CL) values in animal species were allometrically scaled for predicting human clearance. Unbound fractions (f(u)) of drug in plasma in rats and humans were obtained from the literature. A model was developed to predict human CL: CL=33.35 ml/min x (a/Rf(u))(0.770), where Rf(u) is the f(u) ratio between rats and humans and a is the coefficient obtained from allometric scaling. The new model was compared with simple allometric scaling and the "rule of exponents" (ROE). Results indicated that the new model provided better predictability for human values of CL than did ROE. It is especially significant that for the first time the proposed model improves the prediction of CL for drugs illustrating large vertical allometry.
Tang
Huadong
H
Department of Pharmaceutical Sciences, College of Pharmacy, The University of Arizona, Tucson, AZ 85721. USA.
Mayersohn
Michael
M
D020003:1-Octanol / Q000737:chemistry*; D000818:Animals; D006801:Humans; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D004364:Pharmaceutical Preparations / Q000097:blood*; D010599:Pharmacokinetics; D051381:Rats; D013045:Species Specificity; D014867:Water / Q000737:chemistry
D004364:Pharmaceutical Preparations; D014867:Water; D020003:1-Octanol