EP0240189A2
Expired / Lapsed
EP
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Apparatus for iontophoresis application of medicaments
Assignee: University of Utah Research Foundation Inc
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Filing: 1987-03-11
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Granted: —
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Expires: 2007-03-11
Abstract
Abstract Apparatus for administering known quantities of medicaments by iontophoresis while avoiding burns caused by extremes in the pH of the medicament medium during passage of an electric current is disclosed. It has been found that, as iontophoresis progresses in conventional iontophoresis systems, the electrolysis of water occurs to produce hydrogen or hydroxyl ions at the interface of the electrode and medicament medium. Since these ions are highly mobile, they are transported directly into the skin of patient in preference to the larger medicament ions. Thus, extreme changes in pH are experienced which result in burns due to the acidification of alkalinization of the medicament medium and passage of electric current through the skin. The present invention also avoids the production of other competing ions by employing a reactive electrode. The electrode and the medicament are chosen such that the electrode will react with the complementary ion (the ion which forms upon the dissociation of the medicament in solution) to form an insoluble material.
Inventors
- 👤 Thomas J. Petelenz
- 👤 Jiri Janata
- 👤 Robert L. Stephen
- 👤 Stephen C. Jacobson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 23:16
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/0404; A61N1/0408; A61N1/0428; A61N1/0432
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
194 words
An iontophoresis system for delivering a medicament to a patient, said medicament being dissolved in a medium to form active medicament ions and complementary ions, characterised in that said iontophoresis system comprises: a first electrode constructed of a material which is capable of reacting with the complementary ions to form a product which is insoluble in the medicament solution; a second electrode; means for placing the first electrode in communication with the medicament solution; means for placing the medicament solution in communication with a patient such that the solution is disposed between the first electrode and the patient; means for placing the second electrode in communication with the patient at a point on said patient distal from said first electrode; and means for applying an electrical voltage difference between the first and second electrodes, said voltage difference being sufficient to transport the medicament ions through the skin of the patient and to form an insoluble precipitate by the reaction of the complementary ions with the first electrode, thereby removing ions from the medicament medium which would compete for charge transport with the medicament ions and reduce the amount of medicament administered to the patient.
Claim 2
Dependent Claim
194 words
An iontophoresis system for delivering a medicament to a patient, said medicament being dissolved in a medium to form active medicament ions and complementary ions, characterised in that said iontophoresis system comprises: a first electrode constructed of a material which is capable of reacting with the complementary ions to form a product which is insoluble in the medicament solution; a second electrode; means for placing the first electrode in communication with the medicament solution; means for placing the medicament solution in communication with a patient such that the solution is disposed between the first electrode and the patient; means for placing the second electrode in communication with the patient at a point on said patient distal from said first electrode; and means for applying an electrical voltage difference between the first and second electrodes, said voltage difference being sufficient to transport the medicament ions through the skin of the patient and to form an insoluble precipitate by the reaction of the complementary ions with the first electrode, thereby removing ions from the medicament medium which would compete for charge transport with the medicament ions and reduce the amount of medicament administered to the patient.
Claim 3
Dependent Claim
34 words
A system according to Claim 1 characterised in that it further comprises means for maintaining the voltage at the interface between the first electrode and the solution below the electrolysis voltage of the medium.
Claim 4
Dependent Claim
31 words
A system according to Claim 2 characterised in that it further comprises a sensing electrode capable of monitoring the voltage at the interface of the first electrode and the medicament solution.
Claim 5
Dependent Claim
50 words
A system according to Claim 2 characterised in that the voltage at the interface of the first electrode and the medicament medium is controlled by terminating the current flow at the first electrode as the voltage at said interface approaches the voltage at which electrolysis of the medium can occur.
Claim 6
Independent Claim
19 words
A system according to any of the preceding Claims characterised in that the medicament solution is an aqueous solution.
Claim 7
Dependent Claim
41 words
A system according to Claim 5 characterised in that the first electrode is the anode and wherein the voltage at the interface between the first electrode and the medicament medium is maintained below about 1.23 volts versus a Standard Hydrogen Electrode.
Claim 8
Dependent Claim
41 words
A system according to Claim 5 characterised in that the first electrode is the cathode and wherein the voltage at the interface between the first electrode and the medicament medium is maintained below about 0.83 volts versus a Standard Hydrogen Electrode.
Claim 9
Dependent Claim
26 words
A system according to Claim 5 characterised in that the first electrode reacts with the complementary ions at a voltage below the electrolysis voltage of water.
Claim 10
Independent Claim
21 words
A system according to any of the preceding Claims characterised in that said first electrode is constructed of silver or lead.
Claim 11
Independent Claim
21 words
A system according to any of the preceding Claims characterised in that said complementary ions are chloride ions or sulfate ions.
Claim 12
Independent Claim
18 words
A system according to any of the preceding Claims characterised in that said medicament ions are a narcotic.
Claim 13
Independent Claim
22 words
A system according to any of the preceding Claims characterised in that the medicament is selected from morphine, hydromorphone, oxymorphone, and methadone.
Claim 14
Independent Claim
19 words
A system according to any of Claims 1 to 11 charaterised in that the medicament is an anesthetic agent.
Claim 15
Dependent Claim
27 words
, 14. A system for delivering a medicament to a patient according to any of Claims 1 to 11 characterised in that the medicament is lidocaine hydrochloride.
Claim 16
Independent Claim
29 words
A system according to any of the preceding Claims characterised in that the medicament solution containing the medicament ions comprises a gel, a cream, a gum or a foam.
Claim 17
Independent Claim
22 words
A system according to any of the preceding Claims characterised in that the medicament solution comprises a hydrogel containing the medicament ions.
References Cited (Backward Citations)
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