Abstract: A drug formulation chamber for an intravenous administration set is provided. The intravenous administration set includes a container of an IV fluid, a drip chamber, a drug formulation chamber, and an adapter-needle assembly. The drug formulation chamber has a fluid inlet and a fluid outlet for maintaining a flow of IV fluid through the chamber. A portion of the chamber wall is comprised of a window material which allows the drug to diffuse therethrough but which prevents convective loss of the IV fluid. A flow distributor is provided within the chamber for distributing the flow of IV fluid along the interior surface of the window. A transdermal-type drug delivery device is adhered to the exterior surface of the window. Drug is delivered by the delivery device through the window and into the flowing IV fluid. The device delivers drug into the IV fluid at a rate that is independent of the flow rate of IV fluid through the formulation chamber.