在製藥工業中，藥量特性之研究常被應用於藥理學、毒物學及臨床試驗中。藥量特性之研究同時在臨床試驗中的第一階段的藥物安全性及第二階段的藥物有效性中扮演著重要的角色。透過藥量特性的研究，使我們對於藥物的開發有著更深一層的認識，並可藉此縮短藥物核准上市的時間。

在多數的情況下，我們對於藥物動力學之參數與藥物劑量間的線性關係，有著特別的興趣。基於這個目的，一些典型的方法即是由一般線性模式發展而成的。然而，這些典型的統計方法常遇到下列的難題而違反其假設：（一）不同藥物劑量間的異質變異性。（二）不滿足常態性的假設。針對這些問題，我們藉由比較不同劑量間的斜率關係的無母數檢定程序來評估其線性關係並刻劃出藥物的反應曲線，文中並藉此方法舉出交叉實驗之實例。

The problem of characterizing dose response curve for a pharmacokinetic parameter over a specific dose range is considered. In many cases, it is of interest to determine dose linearity (or dose proportionality) between the pharmacokinetic parameters and dose levels. For this purpose, several classical methods based on a general linear model procedure are available. However, two difficulties commonly encountered, namely (i) heterogeneity of the varibility at different dose levels and (ii) violation of the normality assumptions, often make the classical methods not applicable. To account for these problems, we propose a general nonparametric test procedure by comparing the slopes at different dose level to asses dose linearity and to characterize dose response curve. An example concerning the study of dose response of a compound based on a four-way crossover experiment is presented.