Abstract
The transfer of drug dissolved in an oil vehicle into an aqueous solution was studied in vitro method with modified Sartorius Absorption Simulator. On the basis of previous study concerning the drug transfer at an early stage, the whole stage of the transfer was discussed by long-time measurement. The transfer behavier of drug from an oil vehicle to an aqueous solution was expressed by the equation Q=(a/b)(1-e-bt) where Q is the total amount of drug transfered, t the time passed and a and b the transfer constants. The equation was theoretically derived from a drug transfer model.
