A General Strategy for the Identification of Age, Period, Cohort Models: A Mechanism Based Approach

A dry-state iontophoretic drug delivery device (10, 20) is provided. The device has drug and electrolyte reservoirs (15, 16) which are initially in a non-hydrated condition. In one embodiment of the invention, a passageway (21, 22) is provided through the backing layer (13) and the electrode layer (11, 12) of both the donor electrode assembly (8) and the counter electrode assembly (9). Water or other liquid can be introduced through these passageways (21, 22) in order to hydrate the drug and electrolyte reservoirs (15, 16) and activate the device (10). In another embodiment of the device (20), the drug and electrolyte reservoirs (15, 16) are initially separated from their respective electrodes (11, 12). After the reservoirs (15, 16) are hydrated, they are placed in electrical contact with their respective electrodes (11, 12). By joining the reservoir (15, 16) to the electrode (11, 12) after hydration occurs, delamination problems are reduced.