| abstract |
Rate-controlled transdermal delivery devices are disclosed which utilize an in-line adhesive to maintain the device on the skin and deliver an agent which is a solvent for the in-line adhesive. The initial equilibrated concentration of the agent in the agent reservoir and the adhesive is below saturation and the reservoir comprises the agent dissolved in a solvent with respect to which the rate controlling element of the device is substantially impermeable. In preferred embodiments the initial loading of the agent in reservoir is sufficient to prevent the activity of the agent in the reservoir from decreasing by more than about 50% and preferrably no more than about 25% during the predetermined period of administration; and the thicknesses of the adhesive, rate controlling membrane and reservoir layers are selected so that at least 50% and, preferrably at least 75% initial equilibrated agent loading is in the reservoir layer. The devices are usable to delivery oily non-polar agents which are liquid at body temperatures such as benztropine and secoverine. |