14776 IUPAC Gold Book - isobole approach 10.1351/goldbook.14776 14776 current 1 Approach used to visualize or quantify joint action of chemical mixtures by plotting a graph (isobologram) of equally effective dose pairs (isoboles) for a single effect level. A particular effect level is selected, such as \(\pu{50\%}\) of the maximum, and doses of drugs \(\ce{A}\) and \(\ce{B}\) (each alone) that give this effect are plotted as axial points in a Cartesian plot. The straight line connecting \(\ce{A}\) and \(\ce{B}\) is the locus of points (dose pairs) that will produce this effect in a simply additive combination. This line of additivity allows a comparison with the actual dose pair that produces this effect level experimentally. PAC, 2009, 81, 829. 'Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)' on page 902 (https://doi.org/10.1351/PAC-REC-08-07-09) https://goldbook.iupac.org/terms/view/14776/html https://goldbook.iupac.org/terms/view/14776/json https://goldbook.iupac.org/terms/view/14776/plain Citation: 'isobole approach' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14776 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-08T23:37:02+00:00