ABSTRACT
For most compounds, in this series of barriers the luminal membrane of the enterocyte is the most predominant resistance in uptake. The transport of a compound over a cellular barrier is dependent on the physicochemical characteristics of both the compound and the cellular barrier. For the majority of therapeutically active compounds their properties are such that they are well absorbed after oral intake, or, if another route of administration is chosen like pulmonal, uptake into the systemic circulation is not hampered. For these compounds the physicochemical parameters are favorable for absorption.
