Abstract: Irbesartan is a beneficial drug against hypertension and other diseases. Although it is a polydynamic drug, it suffers from high lipophilicity. New formulations of the drug may increase its efficient pharmacological profile. Towards this aim, we have studied the interactions of irbesartan in simple or complexed form with 2-hydroxypropyl-cyclodextrin in micelles. The interactions of the drug in the two forms in the micelle environment are discussed. Of special interest, is the highly flexibility of the spacer phenyl ring.