title: Thermodynamic basis for expressing dose logarithmically.
abstract: The current explanations for using a logarithmic scale for the dose of a chemical, administered to a biological system, have all been empirical. There is a fundamental, thermodynamic reason why a logarithmic scale must be used. The chemical potential is the effect that a chemical exerts on any system, including biological systems. The chemical potential of a chemical in any system is directly proportional to the logarithm of its activity or concentration. Lack of understanding of this concept and the consequent use of a linear scale for dose has led to misinterpretation of many biological experiments.
authors.affiliation: Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA. bwaddell@louisville.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Waddell
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004358:Drug Therapy / Q000379:methods / Q000639:trends; D008970:Molecular Weight; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D004364:Pharmaceutical Preparations