مروری بر تازههای سامانه های دارورسانی اسمزی

Abstract

The osmosis phenomenon is not only essential from physiologic and therapeutic points of view but is important in the design as well as formulation of some drug delivery systems.In fact,two different classes of novel drug delivery systems I.E.The osmotic pumps and the pulsatile systems are based on the principle of osmosis. Drug release from the osmotic pumps occurs in a controlled zero order fasion which prevents drug level fuctuations in blood decreases drug side effects,reduces daily frequency of drug administration and enhances patient compliance. Drugs with moderate to high aqueous solubility are formulated in one compartment osmotic pumps whereas drugs possessing low aqueous solubility are presented as two compartment osmotic systems. An important property of these systems is that the drug release from these does not depend on the pH,composition and motility of the GI tract.The pulsatile andor multi stage osmotic systems release the drug at predetermined times which is of considerable importance in therapeutics is that not only they reduce daily dosage frequency but they have vital prophylaxy importance for combating diseases such as myocardial infarction and stroke which attack at some specific hours of day E.g.Early morning in this thesis recent advances in the technology of the osmotic delivery systems have been reviewed and examples of such systems have been provided and discussed.