An apparatus, comprising: a degradable structure comprising a first reservoir of a plurality of reservoirs, wherein the first reservoir is implemented in a first form selected from a list of forms consisting of: a) a solid structure, such as a container or cup, a flexible bag, or a sponge; and, b) a carrier material, such as a foam, a mousse, a hydrogel, a thin film or membrane, or a bundle or mass of fibrous material; and a second reservoir of the plurality of reservoirs wherein the second reservoir is implemented in a second form selected from the list of forms and the second form is different from the first form, each of the plurality of reservoirs containing a volume of iontophoretic fluid and the degradable structure including a delivery interface configured to be placed in operative apposition with a tissue surface within a nasal cavity of a subject, the iontophoretic fluid including a therapeutic substance; and an electrode device including a proximal portion disposed outside of a nasal cavity and a distal portion configured to extend into the nasal cavity into engagement with a portion of the degradable structure, the electrode device comprising a plurality of electrodes, each electrode being operatively engaged with one of the plurality of reservoirs and the electrode device configured to apply a current to the degradable structure such that an amount of therapeutic substance is delivered to a target area below the tissue surface, the degradable structure configured to maintain the delivery interface against the tissue surface for at least a first predefined period of time during which current is being applied by the electrode device to the degradable structure, the degradable structure further configured to degrade over a second period of time after being disposed within the nasal cavity. a degradable structure comprising a first reservoir of a plurality of reservoirs, wherein the first reservoir is implemented in a first form selected from a list of forms consisting of: a) a solid structure, such as a container or cup, a flexible bag, or a sponge; and, b) a carrier material, such as a foam, a mousse, a hydrogel, a thin film or membrane, or a bundle or mass of fibrous material; and a) a solid structure, such as a container or cup, a flexible bag, or a sponge; and, b) a carrier material, such as a foam, a mousse, a hydrogel, a thin film or membrane, or a bundle or mass of fibrous material; and a second reservoir of the plurality of reservoirs wherein the second reservoir is implemented in a second form selected from the list of forms and the second form is different from the first form, each of the plurality of reservoirs containing a volume of iontophoretic fluid and the degradable structure including a delivery interface configured to be placed in operative apposition with a tissue surface within a nasal cavity of a subject, the iontophoretic fluid including a therapeutic substance; and an electrode device including a proximal portion disposed outside of a nasal cavity and a distal portion configured to extend into the nasal cavity into engagement with a portion of the degradable structure, the electrode device comprising a plurality of electrodes, each electrode being operatively engaged with one of the plurality of reservoirs and the electrode device configured to apply a current to the degradable structure such that an amount of therapeutic substance is delivered to a target area below the tissue surface, the degradable structure configured to maintain the delivery interface against the tissue surface for at least a first predefined period of time during which current is being applied by the electrode device to the degradable structure, the degradable structure further configured to degrade over a second period of time after being disposed within the nasal cavity. <EOS>