IN VITRO DISSOLUTION RATES OF AMINOREX DOSAGE FORMS AND THEIR CORRELATION WITH IN VIVO AVAILABILITY

The object of the study was to develop an oral dosage form of aminorex which would produce prolonged, stable plasma levels of total drug. Since no definite set of dissolution conditions exists for the evaluation of the in vivo availability of a given drug, an arbitrary set of dissolution conditions was chosen. A prioriit was assumed that a correlation existed between in citro dissolution and in vivo availability. If this were true, changes in dosage form release characteristics could be evaluated in vitro before going to man. In vivo availability was determined in human subjects, by determination of total plasma radioactivity following administration of aminorex‐14C. Several of the subjects were crossed over from one dosage form to another. Good correlation was obtained between in vitro dissolution and in uiuo absorption rates. In vivo absorption rates of intact drug were calculated from the plasma data for total radioactivity. A one‐compartment open model was used to describe the system. Dosage forms which pro duced prolonged blood levels of radioactivity were found to give prolonged clinical response. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company