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WO1996009851A1 - Procede de preparation d'electrodes en chlorure d'argent destinees a des dispositifs d'administration de medicaments iontophoretiques - Google Patents

Procede de preparation d'electrodes en chlorure d'argent destinees a des dispositifs d'administration de medicaments iontophoretiques Download PDF

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Publication number
WO1996009851A1
WO1996009851A1 PCT/US1995/012398 US9512398W WO9609851A1 WO 1996009851 A1 WO1996009851 A1 WO 1996009851A1 US 9512398 W US9512398 W US 9512398W WO 9609851 A1 WO9609851 A1 WO 9609851A1
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Prior art keywords
silver
silver chloride
matrix
chloride
quenching
Prior art date
Application number
PCT/US1995/012398
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English (en)
Inventor
Vilambi Nrk Reddy
Philip G. Green
Original Assignee
Becton Dickinson And Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Becton Dickinson And Company filed Critical Becton Dickinson And Company
Priority to AU37289/95A priority Critical patent/AU3728995A/en
Publication of WO1996009851A1 publication Critical patent/WO1996009851A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/0404—Electrodes for external use
    • A61N1/0408—Use-related aspects
    • A61N1/0428—Specially adapted for iontophoresis, e.g. AC, DC or including drug reservoirs
    • A61N1/0432—Anode and cathode
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/0404—Electrodes for external use
    • A61N1/0408—Use-related aspects
    • A61N1/0428—Specially adapted for iontophoresis, e.g. AC, DC or including drug reservoirs
    • A61N1/0432—Anode and cathode
    • A61N1/0436—Material of the electrode

Definitions

  • the present invention relates to iontophoresis and more particularly to a method of preparing a low cost manufacturable silver chloride electrode suitable for use as a cathode in iontophoretic drug delivery devices.
  • transdermal drug delivery systems there are two types of transdermal drug delivery systems, i.e., "passive” and “active.”
  • passive transdermal systems chemical potential gradients provide the dominant diving force to deliver the drug through the skin.
  • a patch containing the drug is applied to the surface of the body and the drug moves into the body predominantly driven by diffusion controlled transport.
  • passive transdermal systems include: delivery of nicotine, nitroglycerine, scopolamine, application of topical anesthetic to provide localized pain relief.
  • Iontophoresis In active transdermal systems, additional user assisted driving forces, either electrical (iontophoresis) or ultrasound (pho ⁇ ophoresis), are used to control the delivery of the drugs through the skin.
  • Iontophoresis In iontophoretic devices for delivering ionized drugs through the skin have been known since the early 1900's. Iontophoresis, according to Stedma ⁇ 's Medical Dictionary, is defined as "the introduction into the tissues, by means of an electric current , of the ions of a chosen medicament.” In iontophoretic transdermal systems electric potential gradients provide the dominant driving force to deliver the ionized drug through the skin.
  • an iontophoretic patch containing the drug is applied to the surface of the body, controlled current is driven through the patch via electrodes in contact with the patch and the drug moves into the body predominantly driven by migration controlled transport due to electric fields setup in the iontophoretic patch by the applied current.
  • iontophoretic transdermal systems include: delivery of pilocarpine in diagnosing cystic f ibrosis, delivery of topical anesthetic to name a few.
  • the iontophoretic patch primarily consists at a minimum of two compartments, an anode and a cathode, each of which are individually in contact with the body.
  • the electrode compartments house the electrodes in contact with the ionic media and are disposed to be in intimate ionic contact with some portion of the body through the skin, to complete the internal electrical circuit.
  • the electrodes are connected externally to a power supply to complete the external electrical circuit. During operation the entire system, power source, electrode, electrolyte, the skin and the body, forms one integrated electrochemical cell
  • the electrode connected to the positive pole of the power supply is called the anode and the electrode connected to the negative pole of the power supply is called the cathode.
  • the current is turned on at the power supply, current flows from the anode to the cathode in the system controlled externally (to the patch) by electron transport and internally (inside the patch between the electrodes) by ion transport.
  • the electrodes act as transducers coverting electron transport to ion transport via an electron transfer reaction (electrochemical reaction) at the electrode
  • iontophoresis can be used to deliver the ionized drug across the skin separator into the body
  • the most commonly used cathode in iontophoretic systems is the Ag/AgCI cathode.
  • the standard thermodynamic reduction equilibrium potential for the Ag/AgCI couple is 0.222V vs NHE (Normal Hydrogen Electrode).
  • the desired electrochemical reaction at the cathode during iontophoresis is the reduction of AgCI to Ag:
  • SU 1132210 teaches preparing a silver chloride electrode on a silver matrix by treating the silver base with a hydrogen peroxide solution containing chloride.
  • GB 2215844 discloses a silver/silver chloride electrode prepared by vigorously stirring fine silver particles suspended in an aqueous chloride salt solution, slowly adding an aqueous silver salt solution while maintaining the suspension so that particles at nucleatio ⁇ sites form silver chloride particles, and, recovering the silver/silver chloride particles. The resulting silver particles coated with silver chloride are then formed into an electrode.
  • the silver/silver chloride electrodes were intended to be used as reference electrodes, with no functional requirement of supporting a current being driven through them as is required of a cathode for iontophoresis.
  • the most common technique for preparing iontophoretic AgCI cathodes involves electrolytic oxidation of Ag to AgCI in acid chloride environment.
  • the desired electrochemical reaction is:
  • Electrolytic chloriding also demands use of pure silver as feed stock for the conversion process. However during the conversion process less than 50% is typically chlorided to satisfy electron conduction requirements resulting in use of pure silver as a current collector in the electrode. It must be pointed out that the cathodic reaction does not require Ag as reactant and in fact pure silver is produced as a product of the cathodic reaction.
  • the use of pure Ag as current collector in electrolytic AgCI cathodes adds to the material cost of the cathode.Further in the electrolytic process the uniformity of AgCI la ⁇ down is controlled by the current distribution on the electrode in the conversion cell. Any non uniform current distribution on the electrode surface (including edge effects) will result in selective chloriding weakening the mechanical integrity and reducing the reliability of the electrodes.
  • the conventional method for preparing silver chloride electrodes by electrolytically chloriding silver electrodes suffers from performance, manufacturing and cost related problems.
  • the lack of low cost, easily and rapidly prepared reliable silver chloride electrodes limits the availability of iontophoretic devices.
  • the present invention of a method for preparing an active silver chloride electrode provides an easily manufactured, reliable, low cost, high capacity cathode (more than 2 mA hr/cm?) which will facilitate the use of iontophoresis as a drug delivery technique.
  • An active silver chloride electrode suitable for long duration use as a cathode in an iontophoretic drug delivery system may be prepared in a few seconds using the method of the present invention from low cost materials.
  • the currently available preparative methods for active silver chloride electrodes require hours and high cost materials to provide an electrode with similar or deficient functional properties to electrodes prepared by the method of the present invention.
  • a method for preparing a silver chloride electrode suitable for use as a cathode for an iontophoretic device includes an electrically conductive matrix which has a surface to serve as an electrode.
  • the conductive matrix is placed in molten silver chloride.
  • the method for preparing a silver chloride electrode preferably then includes allowing the conductive matrix sufficient residence time in the silver chloride melt to produce a substantially continuous silver chloride coating having a thickness on at least a portion of the conductive matrix.
  • the method then includes withdrawing the conductive matrix from the molten silver chloride. After withdrawal of the conductive matrix from the silver chloride the method preferably includes cooling / quenching the conductive matrix and allowing a sufficient time to cool and harden the silver chloride coating.
  • Suitable materials for the conductive matrix include but are not limited to, silver, copper plated with silver, platinum, zinc plated with silver, tin plated with silver, carbon, carbon plated with silver, carbon impregnated with a binding agent and plated with silver.
  • the conductive matrix is preferably dipped in a vessel with molten silver chloride.
  • the silver chloride application may either include electrolytically coating a silver / silver-plated matrix with silver chloride at a temperature below the melting point of silver chloride or applying a finely divided powder of silver chloride to the surface of the conductive matrix. Both of the alternative methods of application result in formation of a discontinuous coating of silver chloride on the surface of the conductive matrix.
  • the method then includes heating the applied discontinuous silver chloride coating above the melting temperature of silver chloride, thus, fusing the silver chloride into a continuous coating and then hardening the now continuous coating by cooling/quenching.
  • Fig. 1 is a schematic representation of an iontophoretic drug delivery device having a cathode formed by the method of the present invention
  • Fig. 2a is a schematic representation of a conductive matrix before applying a silver chloride coating in accordance with the method of the present invention, wherein the conductive matrix a solid conductive matrix;
  • Fig. 2b is a schematic representation of the solid conductive matrix illustrated in Fig. 2a with a silver chloride coating applied thereon in accordance with the method of the present invention
  • Fig. 2c is a schematic representation of a silver chloride electrode of the present invention after a period of use as a cathode in an iontophoretic device;
  • Fig.2d is a schematic representation of a conductive matrix before applying a silver chloride coating in accordance with the method of the present invention, wherein the conductive matrix is a pourous conductive matrix;
  • Fig. 2e is a schematic representation of the pourous conductive matrix illustrated in Fig. 2d with a silver chloride coating applied to both sides of the matrix with the method of the present invention.
  • Fig. 3 is a process flow diagram for the method of the present invention for preparing a silver chloride cathode.
  • Fig. 4a is a graph depicting single electrode potential data for a AgCI coated Ag mesh cathode prepared by the method of the present invention as described in Example 1.
  • Fig. 4b is a graph depicting single electrode potential data for a AgCI coated Ag plated Cu mesh cathode prepared by the method of the present invention as described in Example 2.
  • an iontophoretic device 10 includes a power source 20, a controller 22, an anode assembly 30 and a cathode assembly 40 which are electrically interconnected with electrical conductors 45 to form a complete electrical circuit 60 when device 10 is mounted on a skin surface 50 of a patient and activated.
  • Device 10 further includes a reservoir 31 and an anode conductive matrix 34 as part of anode assembly 30 and a reservoir 41 and a cathode conductive matrix 44 as part of cathode assembly 40 as well as a housing 100 (schematically shown in phantom), for holding the anode and cathode assemblies to the skin, to the power source, to the controller, and to each other.
  • power source 20 In order for electrical current to flow through the device and the skin, electrons must move between anode assembly 30 and cathode assembly 40 through power source 20 and controller 22 through conductors 45, with an ionic flow between anode assembly 30 and cathode assembly 40 through the body of the patient.
  • the function of power source 20 is to provide a source of required current and voltage to operate the iontophoretic device.
  • Current conduction inside the anode/cathode reservoir is via ion transport and is utilized to deliver a medicament having a charge from one or both reservoirs into the patient through skin surface 50.
  • a typical anode contains a positively lonizable drug molecule D, water and an electrolyte with chloride as anion, preferably sodium chloride.
  • the cathode reservoir may contain just an electrolyte, preferably sodium chloride.
  • the electrochemical reaction occurring at the anode is:
  • the drug and anolyte cations will be transported from the anode patch into the body while the chlroide anions from the body will be transported into the anolyte.
  • the electrochemical reaction at the cathode is:
  • the catholyte anions and the chloride anions produced at the electrode will be transported into the body whereas the sodium cations from the body will be transported into the catholyte.
  • a silver mesh or silver foil matrix is electrolytically chlorided, i.e., an electric current is applied to the silver matrix in a solution containing chloride ion, so that silver is oxidized to silver chloride forming a coating on the silver matrix. Since a silver matrix is required, the initial cost of the electrode is significant, and since the generation of silver chloride is done electrolytically, the deposition of silver chloride will likely be discontinuous and not uniform and generally is not physically durable. This is especially true when making high capacity electrodes or those electrodes suitable for long duration use. Generation of milligram quantities of silver chloride electrolytically requires considerable time, considerable silver and, such a process is not easily automated. As was shown above, silver is not even required for the cathode reaction, it is generated by reduction of silver chloride during the iontophoresis.
  • Fig. 2b schematically shows a silver chloride electrode 70 prepared by the preferred method suitable for use in a cathode assembly in an iontophoretic delivery device.
  • the preferred method includes providing a conductive matrix 44 having a surface 42 with a means for connecting 43 the conductive matrix 44 to device 10. These means 43 may be an uncoated extension of the conductive matrix, a wire, a printed circuit conductor to which the conductive matrix is electrically connected and the like.
  • the method then includes providing a station which includes silver chloride.
  • the station preferably includes a vessel containing molten silver chloride, and the matrix is preferably dipped into the melt.
  • the preferred method then provides a quenching bath, preferably water.
  • the elements for manipulating the conductive matrix may simply be forceps or tongs.
  • the conductive matrix is then engaged with the manipulating elements and placed into the silver chloride station for a sufficient amount of time to allow the matrix to acquire a substantially continuous coating of the silver chloride on at least a portion of the surface of the conductive matrix.
  • the conductive matrix having the coating of silver chloride on its surface is then preferably withdrawn from the silver chloride station and transferred to the quenching station.
  • the matrix with the silver chloride on its surface preferably is allowed to remain for suf icient time for the silver chloride coating on the surface of the conductive matrix to cool to a hardened state.
  • the quenching station includes a water bath in which the conductive matrix is placed and allowed sufficient time for the silver chloride to cool to a hardened state.
  • the conductive matrix preferably is then removed from the quenching station and disengaged from the manipulative elements providing completed silver chloride electrode 70 suitable for use in a cathode assembly in an iontophoretic device.
  • Suitable materials for forming the conductive matrix include, but are not limited to, silver, copper plated with silver, zinc plated with silver, platinum, tin plated with silver, carbon, carbon plated with silver, carbon with a suitable binder and carbon with a suitable binder plated with silver.
  • the purpose of the silver plating on the copper, tin and the zinc matrices, is to prevent reaction of the copper, tin or the zinc with molten silver chloride. Since the silver serves only to render the conductive copper, tin or zinc inert to the molten silver chloride, the actual amount of silver required is very small.
  • a suitable binder for carbon includes inorganic materials such as clay or organic resins commonly used as fluxes in the semiconductor industry mixed with carbon in a range between about thirty percent to about ninety percent carbon.
  • carbon is intended to include forming a suitable matrix from carbon fibers, including woven materials, non 5 woven materials and the like.
  • preferred conductive matrix 44 acquires a substantially continuous coating of silver chloride 46 when passed through the preferred molten silver chloride.
  • preferred electrode 70 prepared by the method of the present invention is suitable to be installed in
  • the conductive matrix is a pourous conductive matrix and as shown in Fig. 2e the silver chloride may be caoted on both sides of the pourous matrix.
  • An example of a pourous matrix is a metal or metallic mesh.
  • the conductive matrix on which the silver chloride is coated on both sides is pourous so that the electrons may pass through the matrix to reach and utilize the silver chloride on the other side.
  • the conductive matrix is all silver.
  • silver is formed by the reduction of silver chloride at the cathode by acquisition of an electron during iontophoresis.
  • the present method is suitable for preparing an electrode with silver or other non-silver conductive materials as the conductive matrix.
  • a silver chloride electrode where silver is used as the conductive matrix prepared by the instant method is physically more durable and uniform than one prepared electrolytically.
  • the electrode of the present invention may be loaded with 35 sufficient silver chloride to meet duration of use and quantity requirements as applicable for intended use of each electrode manufactured.
  • the time required for preparation of a silver chloride electrode by the method of the present invention is measured in seconds using silver as the conductive matrix compared to hours for an silver chloride electrode of comparable capacity prepared by electrolytic deposition.
  • a copper or other non-silver conductive matrix plated with silver is suitable for forming a silver chloride electrode by the method of the present invention.
  • a copper matrix by itself may not be satisfactory for some applications. If a copper matrix plated with silver is used to form a silver chloride electrode by the common electrolytic generation method, there would need to be sufficient silver plated on the matrix to form the desired amount of silver chloride.
  • a comparable capacity silver chloride electrode produced with a copper conductive matrix by the method of the present invention needs only sufficient silver plated onto the copper matrix to prevent undesirable side reactions between the copper and the molten silver chloride.
  • All of the silver chloride needed to provide the same functional capability as the silver/silver chloride electrode, for use as a cathode in an iontophoretic device, is coated onto the conductive matrix using the same method as would be used for a pure silver matrix, thereby providing the same cathode functional capability at a greatly reduced cost.
  • the silver chloride layer formed by this method would likely not be uniform, would lack physical integrity and would be discontinuous.
  • the delivery of electrons can be done at a higher current for a shorter time, however, the silver chloride layer formed would surely not be u ⁇ iform.be discontinuous and would not have the physical integrity of an electrode prepared by the method of the present invention.
  • the preferred method may include an intermediate cooling step followed by a return to the molten silver chloride for additional loading of silver chloride.
  • the first pass through the molten silver chloride provides a coating of silver chloride having an initial thickness, with each subsequent pass adding additional thickness and additional mass.
  • Each pass of the conductive matrix through the preferred molten silver chloride requires only seconds. Thus, the total time required, even for high loadings of silver chloride, is small compared to the time required for electrolytic deposition of equivalent amounts.
  • the matrix with the silver chloride coating is preferably then quenched, providing a glassy, hard and durable silver chloride surface.
  • the silver chloride is a vessel having molten silver chloride therein, and the matrix is dipped into the molten silver chloride for the coating step, preferably the intermediate cooling step may simply be a withdrawal from the molten silver chloride for a brief period of time followed by a replicate dipping, or it may include cooling by air or an inert gas.
  • the method of the present invention also includes applying a coating of silver chloride to the conductive matrix at a temperature below the melting point of silver chloride followed by heating the silver chloride coating above its melting point to fuse it, and then quenching it to form a hard glassy surface.
  • the application of silver chloride below the melting point includes, but is not limited to, powder coating, vacuum deposition, or in the case where the conductive matrix is silver, electrolytic generation of silver chloride.
  • the instant method may also include automated localized heating for fusing of the silver chloride coating preferably followed by rapid quenching that would allow the use of flexible web as a carrier in an automated process.
  • automated localized heating for fusing of the silver chloride coating preferably followed by rapid quenching that would allow the use of flexible web as a carrier in an automated process.
  • the present use of controlled localized heating followed by rapid quenching would allow the use of a carrier web which otherwise is unable to directly withstand the melting point of silver chloride (455° C.) and enable the backing to be utilized as part of the reservoir for the cathode as well as the electrode itself, further simplifying the construction of the iontophoretic device.
  • the silver chloride application and the quenching preferably includes inert atmosphere gas blanket on the molten pool to avoid incorporation of impurities into the silver chloride coating. Additionally, while the quenching preferably includes deionized water as the heat transfer agent, it may also include non-reactive gases such as nitrogen, argon, helium and the like as heat transfer agents.
  • Example 1 describes the preparation of a silver chloride electrode on a silver mesh matrix.
  • Example 2 describes the preparation of a silver chloride electrode on a copper mesh matrix plated with about 0.1 mil of silver. Test results are shown in Table 1 comparing the electrode of example 1 with the electrode of Example 2 in a functional model for use as an iontophoretic cathode. The results show that the performance of a silver chloride electrode formed on the silver plated copper matrix is not different than the performance of the silver chloride electrode formed on the all silver matrix.
  • Figure 4a presents the single electrode potential data (versus AgCI wire reference electrode) for the cathode and the anode during the dechloriding test conducted as described in the experimental setup section.
  • the cathode was 2.5cm square Ag mesh (4Ag6.5031 ) thermally coated with approximately 53mg of AgCI melt.
  • the anode was 2.5cm square Ag mesh (6Agl -77); the electrolyte was 150mM saline solution at room temperature with no agitation; and the current density was 0.4mA/sq.cm.
  • the polarization on the cathode at 0.4 mA/sq.cm. is 20mV initially and increases to 50mV at the end of the experiment.
  • the signal stays relatively stable throughout the life of the experiment.
  • the increase in polarization from 20mV to 50mV is due to concentration overpotential effects at the electrode.
  • the low and stable electrode polarization is very encouragining suggesting good electrode performance and a stable electrode structure with easily accessible AgCI reactant and electrolyte.
  • the cathode overpotential increases rapidly exceeding 50mV indicating a change in the electrochemistry at the electrode from silver chloride to water electrolysis.
  • the electrode is practically "dead" for iontophoretic application since the electrolysis of water at the cathode will lead to detrimental pH effects.
  • the coulombic experimental specific capacity of the electrode for AgCI reduction from the above data is calculated to be 9.72 mA-hr/sq.cm.
  • the theoretical specific capacity calculated is 9.9 mA-hr/sq.cm.
  • the percent utilization of AgCI is determined based on the ratio of the experimental specific capacity to the theoretical specific capactiy is then calculated to be 98.2%.
  • Figure 4b presents the single electrode potential data (versus AgCI wire reference electrode) for the cathode and the anode during the dechloriding test conducted as described in the experimental setup section.
  • the cathode was 1.0cm square Ag/Cu mesh "0.1 mil” Ag coated 4Cu7-100) thermally coated with approximately 80mg of AgCI melt.
  • the anode was I.Ocm square Ag mesh (6Agl0077); the electrolyte was I ⁇ OmM saline solution at room temperature with no agitation; and the current density was 0.4mA/sq.cm.
  • the polarization on the cathode at 0.4 mA/sq.cm is 20mV initially and increases to 5lmV at the end of the experiment.
  • the signal stays relatively stable throughout the life of the experiment.
  • the increase in polarization from 20mV to 5lmV is due to concentration overpotential effects at the electrode.
  • the low and stable electrode polarization is very encouraging suggesting good electrode performance and a stable electrode structure with easily accessible AgCI reactant and electrolyte.
  • the coulombic experimental capacity of the electrode for AgCI reduction from the above data is calculated to be 14.3 mA-hr/sq.cm.
  • the theoretical specific capacity calculated is 14.84 mA-hr/sq.cm.
  • the percent utilization of AgCI is determined based on the ratio of the experimental specific capacity to the theoretical specific capactiy is then calculated to be 96.3%.
  • Table 1 presents a comparison of the electrodes of example 1 and example 2 in a functional evaluation of electrochemically accessible silver chloride for the reaction:
  • Electrodes prepared according to Examples 1 and 2 were each installed as a cathode versus a silver mesh anode in test cells containing aqueous 150 millimolar sodium chloride solution. Exposed cathode area was 1 cm? varied from 1 -2.5 cm?. Testing was done under constant current control and the operating current density was 0.4 mA/cm?. The cathode potential was monitored with a Ag/AgCI reference electrode and the testing was stopped when the electrode reaction switched from AgCI reduction to hydrogen evolution (as observed from the change in the cathode polarization). The experimentally available coulombic capacity of the electrode was determined from the current density and the lifetime of the electrode for AgCI reduction electrochemistry.
  • the silver conductive matrix has a higher substrate specific weight because it is a less open and thicker mesh than silver plated copper.
  • the silver plated copper conductive matrix acquired a higher loading of silver chloride than the pure silver because of the different mesh dimensions. This data suggests that the mesh design can be effectvely used to vary and control AgCI loading onto the substrate.
  • the specific capacity of the cathodes tested was in excess of 10 mA.hr/cm?. This implies that at 0.4 mA/cm? current density the cathodes can be safely operated with AgCI reduction electrochemistry in excess of 24 hrs. Also the utilization of the AgCI active mass (as calculated from the experimental and theoretical specific capacities) in the electrodes tested was in excess of 90% suggesting good electrode structure (ionic and electronic) and efficient use of the active electrode material.

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Abstract

L'invention se rapporte à un procédé de préparation d'une électrode en chlorure d'argent appropriée pour être utilisée comme cathode d'un dispositif iontophorétioque. Cette électrode comprend une matrice conductrice dont une surface sert d'électrode, et du chlorure d'argent. Le procédé consiste à placer la matrice conductrice dans le chlorure d'argent sur une durée suffisante, généralement quelques secondes seulement, pour que la matrice conductrice puisse être revêtue de chlorure d'argent. La matrice est ensuite retirée du chlorure d'argent, puis refroidie brusquement, durcissant ainsi le chlorure d'argent. La matrice dont la surface est recouverte du chlorure d'argent durci est ensuite prête à être placée dans un dispositif iontophorétique tel qu'une cathode. De préférence, le procédé consiste à immerger la matrice conductrice dans du chlorure d'argent fondu pour que sa surface soit recouverte d'une couche de chlorure d'argent. Le processus d'immersion peut être renouvelé pour accroître l'épaisseur de la couche de chlorure d'argent en cas de besoin, ce qu'on ne pourrait obtenir en une seule immersion. Les résultats obtenus indiquent qu'une électrode préparée sur une matrice de cuivre plaquée d'argent sont aussi favorables comparés à ceux d'une électrode préparée sur une matrice d'argent pur.
PCT/US1995/012398 1994-09-29 1995-09-25 Procede de preparation d'electrodes en chlorure d'argent destinees a des dispositifs d'administration de medicaments iontophoretiques WO1996009851A1 (fr)

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US08/315,316 1994-09-29

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Cited By (4)

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Publication number Priority date Publication date Assignee Title
WO1999038564A1 (fr) * 1998-01-28 1999-08-05 Alza Corporation Cathodes electrochimiquement reactives pour dispositif d'electrotransport
US6195582B1 (en) 1998-01-28 2001-02-27 Alza Corporation Electrotransport device electrode assembly having lower initial resistance
US6375990B1 (en) 1997-10-09 2002-04-23 Emory University Method and devices for transdermal delivery of lithium
WO2004089464A1 (fr) * 2003-03-31 2004-10-21 Alza Corporation Dispositif d'electrotransport comportant un logement de reservoir dans lequel est dispose un element conducteur souple

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WO1991011216A1 (fr) * 1990-01-26 1991-08-08 Gensia Pharmaceuticals, Inc. Electrode et methode de transfert par iontophorese
WO1991016944A1 (fr) * 1990-05-07 1991-11-14 Alza Corporation Dispositif d'administration iontophoretique

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Publication number Priority date Publication date Assignee Title
WO1991011216A1 (fr) * 1990-01-26 1991-08-08 Gensia Pharmaceuticals, Inc. Electrode et methode de transfert par iontophorese
WO1991016944A1 (fr) * 1990-05-07 1991-11-14 Alza Corporation Dispositif d'administration iontophoretique

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A.ARÉVALO & ALL: "Preparation and reproductibility of a thermal silver-silver chloride electrode", JOURNAL OF APPLIED ELECTROCHEMISTRY, vol. 15, no. 5, pages 727 - 735 *
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6375990B1 (en) 1997-10-09 2002-04-23 Emory University Method and devices for transdermal delivery of lithium
WO1999038564A1 (fr) * 1998-01-28 1999-08-05 Alza Corporation Cathodes electrochimiquement reactives pour dispositif d'electrotransport
US6195582B1 (en) 1998-01-28 2001-02-27 Alza Corporation Electrotransport device electrode assembly having lower initial resistance
US6505069B2 (en) 1998-01-28 2003-01-07 Alza Corporation Electrochemically reactive cathodes for an electrotransport device
WO2004089464A1 (fr) * 2003-03-31 2004-10-21 Alza Corporation Dispositif d'electrotransport comportant un logement de reservoir dans lequel est dispose un element conducteur souple
US8224435B2 (en) 2003-03-31 2012-07-17 Alza Corporation Electrotransport device having a reservoir housing having a flexible conductive element

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