US 5,857,992 AGranted

Device and method of iontophoretic drug delivery

AssigneeAlza Corporation

InventorsRonald P. Haak, J. Richard Gyory, Felix Theeuwes

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Abstract

A selectively permeable membrane (14) is positioned between the agent reservoir (15) and the electrode (11) of a donor electrode assembly (8) in an iontophoretic delivery device (10). Optionally, an electrolyte reservoir (13) is positioned intermediate the electrode (11) and the agent reservoir (15). In certain embodiments, the membrane (14) is permeable to species of less than a predetermined molecular weight and substantially less permeable to species of greater than the predetermined molecular weight. The agent is capable of dissociating into agent ions and counter ions. The size selectivity of the membrane (14), the molecular weight of the agent ions, the molecular weight of the counter ions, and optionally the molecular weight of the electrolyte ions are selected to (A) inhibit agent ions from interacting with the electrode (11), and from permeating into the electrolyte reservoir (13), where they might otherwise be degraded and (B) inhibit electrolyte ions, having a charge similar to that of the agent ions, from permeating into the agent reservoir (15) and competing with the agent ions for iontophoretic delivery into the patient.

Claims17

Dependent claims

An electrically powered iontophoretic agent delivery device including a donor electrode assembly, a counter electrode assembly and a source of electrical power adapted to be electrically connected to the donor and counter electrode assemblies, the donor electrode assembly comprising:

an agent reservoir containing an agent and adapted to be placed in agent transmitting relation with a body surface;
a donor electrode adapted to be electrically connected to the source of electrical power;
a non-hydrated, selectively-permeable membrane between the donor electrode and the agent reservoir and upon hydration being permeable to molecules less than a predetermined molecular weight and substantially less permeable to molecules greater than the predetermined molecular weight;
and,
an electrolyte reservoir containing an electrolyte intermediate the donor electrode and the non-hydrated, selectively permeable membrane,
wherein the agent dissociates into agent ions having a molecular weight less than the predetermined molecular weight and counter ions having a molecular weight greater than the predetermined molecular weight,
wherein the electrolyte dissociates into (i) electrolyte ions having a similar sign charge as the agent ions, and (ii) electrolyte ions having a similar sign charge as the agent counter ions, the electrolyte ions having the same charge as the agent ions having a molecular weight less than the predetermined molecular weight, and the electrolyte ions having the same charge as the counter ions having a molecular weight greater than the predetermined molecular weight;
and
wherein the membrane is capable of being hydrated upon operation of the device.

6 more elements

Dependencies are inferred from the claim text.