The use of compendial dissolution techniques to characterize the performance of oral drug delivery systems is an established area of pharmaceutical science. However, compendial equipment is recognized as being limited in its ability to replicate the dynamic aspects of in vivo dissolution that are associated with dosage form transit through a rapidly changing and complex gastrointestinal lumenal environment. This review provides an overview of noncompendial dissolution models which have been developed to address the deficiencies of the traditional dissolution bath and provide scientists with a way of assessing product performance under physiologically relevant conditions.