摘要: Due to the popularity of topical and transdermal drug delivery, there is a high demand for reliable skin penetration permeation data. Compared in vivo methods, vitro methods enable these data be more easily obtained shorter time. Two dosing regimens are commonly used model delivery vitro, namely, finite infinite dosing. These useful different situations allow absorption parameters determined empirically. The choice between depends upon applicability underlying assumptions given in-use situation. This chapter provides an overview on dose research, discuss advantages limitations such regimens.