AUCは体循環血液中に入った薬物量に比例します。（薬物血中濃度－時間曲線下面積（AUC）　治験ナビ）

Area Under the Curve One of the most important pharmacokinetic parameters is the area under the drug concentration versus time curve within the dosing interval (AUC) because AUC relates dose to exposure. Because the dosing interval is typically once daily or every 24 h on safety studies, the reported AUC is typically AUC0–24 h. AUC is the quantitative measure of the apparent amount of compound at the site from which samples were collected and concentrations measured, which in most cases is the systemic circulation. When sampling occurs from the systemic circulation, it is often an indication of systemic exposure. The simplest method for calculating AUC is the linear trapezoidal rule (Gibaldi and Perrier 1982). (sciencedirect.com)