PTE September Gino Q2

Enquiry service online at www.ptemagazine.com I 1 Oral absorption efficiency can be influenced by several factors, acting independently or in concert. These include the physicochemical properties of the administered agent, human physiology, pathology (including disease state), the way the drug is presented (formulated) and possibly the amount that is administered (dose). Other influences include time of administration, whether the patient is resting or active and body position, for example, recumbent or standing. Optimizing absorption requires knowledge of how these variables affect the drug or formulation. However, it may take many years before such comprehensive knowledge can be gleaned on compound-specific behaviours. In the absence of such detailed insight it may necessary, particularly with novel therapeutic agents being dosed to man for the first time, to design a formulation based on generic considerations of factors affecting absorption, the physicochemical properties of the agent being administered and in vivo or ex vivo findings in animals or animal tissue. Such a strategy can help identify the optimum form of the drug and clarify possibilities and limitations for manipulating its properties to optimize delivery. Hence, good understanding of the physicochemical properties of the drug, and of the anatomy and physiology of the gastrointestinal (GI) tract provides valuable insight on the possibilities and constraints for optimizing oral absorption.