Abstract: High capacity drug reservoirs are provided for incorporation into transdermal drug delivery systems. The drug reservoirs are hydrogels formulated from polyurethanes crosslinked with diisocyanate crosslinking agents or cured with radiation in the presence of a photoinitator. Drug loading as high as 65 to 70 wt. % or higher can be achieved by absorbing drug formulation into the reservoir after hydrogel synthesis. Methods for making and using transdermal systems containing such reservoirs are provided as well.

Abstract: A method for measuring the concentration of a chemical present in a blood stream of a mammalian subject is disclosed. The method involves contacting the subject's skin with a sensor assembly comprised of an ionically conducting material which contacts the skin, a working electrode which is in contact with the ionically conducting material which electrode has a catalytic surface and a mask having an opening therein. The mask is positioned between the skin and the working electrode. When the electrode is activated, chemical is transported through the skin and the ionically conductive material. The mask is positioned so that it blocks the flow into the catalytic surface except for flow which is substantially axially to the catalytic surface. Electrical signal generated at the working electrode is monitored over a period of time and correlated with a concentration of chemical present in the blood stream of the mammalian subject.