AU714537B2

AU714537B2 - Electrotransport device having reusable controller

Info

Publication number: AU714537B2
Application number: AU58522/96A
Authority: AU
Inventors: Tighe M. Belden; Danny J. Cunagin; Philip C. Dretzka; Gary A Lattin
Original assignee: Alza Corp
Current assignee: Alza Corp
Priority date: 1995-05-15
Filing date: 1996-05-01
Publication date: 2000-01-06
Anticipated expiration: 2016-05-01
Also published as: CN1104917C; CH693606A5; NL1003109C2; IE960331A1; AU714537C; IT1285873B1; JPH11505158A; JP2006297132A; JP2008100096A; FR2734162A1; ITTO960397A1; DE19681392T1; WO1996036394A1; MX9708823A; FR2734162B1; GB2317343A; AU5852296A; NL1003109A1; BE1009855A5; GB2317343B

Description

WO 96/36394 PCT/US96/06098 1 1 ELECTROTRANSPORT DEVICE HAVING REUSABLE 2

CONTROLLER

3 4 TECHNICAL FIELD 6 The invention relates to electrotransport drug delivery systems having 7 a drug containing assembly and a reusable controller having an electrically 8 powered control circuit, the assembly and the controller being separably 9 connected by a coupler which establishes electrical connection of the assembly to the controller.

11 12 BACKGROUND ART 13 14 The term "electrotransport" as used herein refers generally to the delivery of an agent a drug) through a membrane, such as skin, mucous 16 membrane, or nails. The delivery is induced or aided by application of an 17 electrical potential. For example, a beneficial therapeutic agent may be 18 introduced into the systemic circulation of a human body by electrotransport 19 delivery through the skin. A widely used electrotransport process, electromigration (also called iontophoresis), involves the electrically induced 21 transport of charged ions. Another type of electrotransport, electroosmosis, 22 involves the flow of a liquid, which liquid contains the agent to be delivered, 23 under the influence of an electric field. Still another type of electrotransport 24 process, electroporation, involves the formation of transiently-existing pores in a biological membrane by the application of an electric field. An agent can be 26 delivered through the pores either passively without electrical 27 assistance) or actively under the influence of an electric potential).

28 However, in any given electrotransport process, more than one of these 29 processes may be occurring simultaneously to a certain extent. Accordingly, the term "electrotransport", as used herein, should be given its broadest WO 96/36394 PCT/US96/06098 2 1 possible interpretation so that it includes the electrically induced or enhanced 2 transport of at least one agent, which may be charged, uncharged, or a 3 mixture thereof, whatever the specific mechanism or mechanisms by which 4 the agent actually is transported.

Electrotransport devices use at least two electrodes that are in 6 electrical contact with some portion of the skin, nails, mucous membrane, 7 or other surface of the body. One electrode, commonly called the "donor" 8 or "active" electrode, is the electrode from which the therapeutic agent is 9 delivered into the body. The other electrode, typically termed the "counter" or "return" electrode, serves to close the electrical circuit through the body.

11 For example, if the agent to be delivered is positively charged, a cation, 12 then the anode is the active or donor electrode, while the cathode serves 13 to complete the circuit. Alternatively, if an agent is negatively charged, 14 an anion, the cathode is the donor electrode. Additionally, both the anode and cathode may be considered donor electrodes if both anionic and 16 cationic agent ions, or if uncharged or neutrally charged agents, are to be 17 delivered.

18 Furthermore, electrotransport delivery systems generally require at 19 least one reservoir or source of the agent to be delivered, which is typically in the form of a liquid solution or suspension. Examples of such donor 21 reservoirs include a pouch or cavity, a porous sponge or pad, and a 22 hydrophilic polymer or a gel matrix. Such donor reservoirs are electrically 23 connected to, and positioned between, the anode or cathode and the body 24 surface, to provide a fixed or renewable source of one or more agents or drugs. Electrotransport devices also have an electrical power source such as 26 one or more batteries. Typically, one pole of the power source is electrically 27 connected to the donor electrode, while the opposite pole is electrically 28 connected to the counter electrode. In addition, some electrotransport 29 devices have an electrical controller that controls the current applied through the electrodes, thereby regulating the rate of agent delivery. Furthermore, WO 96/36394 PCT/US96/06098 3 1 passive flux control membranes, adhesives for maintaining device contact 2 with a body surface, insulating members, and impermeable backing members 3 are other optional components of an electrotransport device.

4 All electrotransport agent delivery devices utilize an electrical circuit to electrically connect the power source a battery) and the 6 electrodes. In very simple devices, such as those disclosed in Ariura et al 7 US Patent 4,474,570, the "circuit" is merely an electrically conductive wire 8 used to connect the battery to an electrode. Other devices use a variety 9 of electrical components to control the amplitude, polarity, timing, waveform shape, etc. of the electric current supplied by the power source.

11 See, for example, McNichols et al US Patent 5,047,007.

12 To date, commercial transdermal electrotransport drug delivery devices 13 the Phoresor, sold by lomed, Inc. of Salt Lake City, UT; the Dupel 14 lontophoresis System sold by Empi, Inc. of St. Paul, MN; the Webster Sweat Inducer, model 3600, sold by Wescor, Inc. of Logan, UT) have generally 16 utilized a desk-top electrical power supply unit and a pair of skin contacting 17 electrodes. The donor electrode contains a drug solution while the counter 18 electrode contains a solution of a bio-compatible electrolyte salt. The 19 "satellite" electrodes are connected to the electrical power supply unit by long 1-2 meters) electrically conductive wires or cables. Examples of desk- 21 top electrical power supply units which use "satellite" electrode assemblies 22 are disclosed in Jacobsen et al US Patent 4,141,359 (see Figures 3 and 4); 23 LaPrade US Patent 5,006,108 (see Figure and Maurer et al 24 US Patent 5,254,081 (see Figures 1 and The power supply units in such devices have electrical controls for adjusting the amount of electrical 2s current applied through the electrodes. Existing commercial electrotransport 27 devices are approved for operation only by trained medical technicians.

28 One important consideration when connecting the "satellite" electrodes to the 29 power supply unit is to make sure that the electrodes are connected with the correct polarity, a satellite donor electrode which contains a cationic ARC 2380 CIP1 Stherapeutic agent must be connected to the positive output of the controller 2 whereas a satellite donor electrode which contains an anionic therapeutic 3 agent must be connected to the negative output of the controller. In order to 4 assist the medical technician to make the correct polarity connections, two approaches have been used. In the first approach, the outputs of the 6 controller have been color coded to the appropriate satellite electrode.

7 In the second approach (used in the CF Indicator sold by ScandiPharm, Inc.), 8 the controller is provided with electrodes in the form of metal stainless 9 steel) plates which are positioned on one side of the controller housing.

The two electrode plates have different geometric shapes one square 11 and one circular). The drug-containing donor gel and the electrolyte- 12 containing counter gel each have a different shape which corresponds to the 13 respective electrode plate shape in order to ensure that the donor and 14 counter gels are placed in contact with the correct correct polarity) electrodes.

s16 More recently, small self-contained electrotransport delivery devices 17 adapted to be worn on the skin, sometimes unobtrusively under clothing, 18 for extended periods of time have been proposed. The electrical components 19 in such miniaturized electrotransport drug delivery devices are also preferably miniaturized, and may be either integrated circuits 21 microchips) or small printed circuits. Electronic components, such as 22 batteries, resistors, pulse generators, capacitors, etc., are electrically 23 connected to form an electronic circuit that controls the amplitude, polarity, 24 timing, waveform shape, etc. of the electric current supplied by the power source. Such small self-contained electrotransport delivery devices are 26 disclosed for example in Tapper US Patent 5,224,927; Sibalis et al US Patent 27 5,224,928 and Haynes et al US Patent 5,246,418. European Patent 28 Application 0 337 642 discloses an iontophoretic device that is light in weight, 29 easily manufactured and assembled, and directly and simply applied to the patient's skin. The device includes two quick connectors.

AMENDED SHEET 1 111 WO 96/36394 PCTIUS96/06098 1 There have recently been suggestions to utilize electrotransport 2 devices having a reusable controller which is adapted to be used with multiple 3 drug-containing units. The drug-containing units are simply disconnected 4 from the controller when the drug becomes depleted and a fresh drugcontaining unit is thereafter connected to the controller. In this way, 6 the relatively more expensive hardware components of the device 7 batteries, LED's, circuit hardware, etc.) can be contained within the 8 reusable controller, and the relatively less expensive donor reservoir and 9 counter reservoir matrices can be contained in the disposable drug containing unit thereby bringing down the overall cost of electrotransport drug delivery.

11 Examples of electrotransport devices comprised of a reusable controller 12 adapted to be removably connected to a drug-containing unit are disclosed in 13 Sage, Jr. et al, US Patent 5,320,597; Sibalis, US Patent 5,358,483; 14 Sibalis et al, US Patent 5,135,479 (Fig. 12); and Devane et al UK Patent Application 2 239 803.

16 Electrotransport devices having reusable controllers and which are 17 adapted to be used with multiple drug-containing units are particularly well 18is suited for drug administration to patients outside of clinic/doctor's office 19is settings for those patients requiring long term medication).

Unfortunately, the existing schemes for ensuring that the drug reservoir 21 of an electrotransport device is connected to the electrode of the correct 22 polarity are not foolproof. This becomes an even greater problem in settings 23 outside of the clinic/doctor's office where the patient is expected to 24 periodically replace the drug-containing unit him/herself. The problem becomes still greater in cases where the patient population tends to be 26 more elderly.

DESCRIPTION OF THE INVENTION It is an object of the present invention, at least in the preferred embodiment, to overcome or substantially ameliorate one or more of the disadvantages of the prior art.

According to a first aspect of the invention there is provided an electrotransport device for delivering a therapeutic agent through a body surface of a patient, the device including: a therapeutic agent-containing unit including first and second reservoirs and first and second electrodes electrically connected to said first and second reservoirs, wherein at least one of the reservoirs contains the therapeutic agent to be delivered; and 00 0: .000 10 a controller having the bipolar electrical power source for providing electric .0 0 so 0 0 current to the electrodes, the controller having first and second connectors for electrically 0 0 a 0 4,40 connecting the first and second poles of the bipolar power source to the first and second electrodes, respectively, wherein the device further includes a coupler which only permits electrical connection between the first electrode and first pole and between the 0 0 15 second electrode and second pole, respectively, when the controller is mated to the 00.0 0 therapeutic agent-containing unit.

0060 0 0 0 0 0 0 0 According to another aspect of the invention there is provided a method for using 0 0 0 an electrotransport device for delivering therapeutic agent through a body surface of a 0.-00: 0. 90: patient, the device including the steps ofproviding a therapeutic agent-containing unit including first and second reservoirs electrically connected to first and second electrodes provided for being electrically connected to first and second poles of a bipolar electrical power source, wherein at least -7one of the reservoirs contains the therapeutic agent to be delivered; providing a controller having the bipolarelectrical power source for providing electric current to the electrodes, the controller having first and second connectors for electrically connecting the first and second poles of the bipolar power source to the first and second electrodes, respectively, wherein the device further includes a coupler which only permits electrical connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit; 10•the electrically and mechanically connecting the therapeutic agent containing unit and the controller; contacting the therapeutic agent-containing unit with the body surface of a patient; and activating the electrical power source delivering the therapeutic agent to the body surface.

15 Preferably the invention provides correct polarity electrical connection between the 00 0 •.drug reservoir of a drug-containing assembly and the reusable controller of an 0000 •0 electrotransport device comprised of a reusable controller adapted to be used with a S•.plurality of drug-containing assemblies.

Preferably the invention provides correct polarity electrical connections in an electrotransport device comprised of a reusable electronic controller adapted to be used with a plurality of single use (for example, disposable) drug-containing units. After the drug has been depleted from the drug-containing unit, the unit is disconnected from the controller and discarded, and then replaced with a fresh one. The controller includes a 7abipolar power source (for example, one or more batteries), and optionally a circuit for controlling the timing, frequency, magnitude, etcetera of the current applied by the device. The drug-containing unit has first and second electrodes, at least one of which contains the therapeutic agent (that is, drug) to be delivered.

In accordance with one embodiment of the invention, the reusable controller is adapted to be electrically coupled to a more limited use (for example, a single use) drugcontaining unit by at least two electrically conductive snap connectors. The snap connectors have different sizes and/or are arranged with different male/female parts in S the different respective units, so that the controller and the drug-containing unit may be S 10 coupled in only one way, that is, with the correct polarity connections.

In an alternative embodiment of the invention, a projecting member is provided on either the controller or the drug-containing unit with a correspondingly shaped hole on the other unit. The positioning of the projecting member and the correspondingly shaped 0 hole are such that the controller and the drug-containing unit may be coupled in only one 00 15 way, that is, with the correct polarity connections.

000 •BRIEF DESCRIPTION OF THE DRAWINGS 0000* S•A preferred embodiment of the invention will now be described, by way of 00 example only, with reference to the accompanying drawings in which: 0 0 0• Figure 1 is a perspective view of an electrotransport device including a reusable controller and a separate drug-containing unit, in an uncoupled configuration, which controller and unit are couplable; Figure 2 is a cross sectional view of the device shown in Figure 1, showing the controller and the drug-containing unit in a coupled configuration; 7b Fig 3 is a perspective view of an electrotransport device including a reusable controller and a separate drug-containing unit, in an uncoupled configuration, which controller and drug unit are couplable; Figure 4 is a perspective view of an electrotransport device including a reusable controller and a separate drug-containing unit, in an uncoupled configuration, which controller and drug unit are couplable in accordance with one embodiment of the invention; :Figure 5 is a perspective view of an electrotransport device with the controller and the drug-containing unit in an uncoupled configuration, the drug-containing unit adapted 10 to slidably engage the controller in accordance with another embodiment of the invention; S: Figure 6 is a bottom view of the device shown in Figure 5 with the controller and the drug-containing unit in a coupled configuration; Figure 7 is a sectional view of the device shown in Figs. 5 and 6, taken along line 15 7-7 shown in Figure 6; Figure 8 is a perspective view of an electrotransport device including a reusable S controller and a separate drug-containing unit in an uncoupled configuration, wherein the controller and drug-containing unit are couplable in accordance with another embodiment of the invention; WO 96/36394 PCTfUS96/06098 8 1 Fig. 9 is a top view of a drug-containing unit in accordance with 2 another embodiment of the present invention; 3 Fig. 10 is a side view of the drug-containing unit shown in Fig. 9; 4 Fig. 11 is a perspective view showing the coupling of a reusable controller to the drug-containing unit illustrated in Figs. 9 and 6 Fig. 12 is a top view of the coupled system shown in Fig. 11; 7Fig. 13 is a top view of a coupled electrotransport system in 8 accordance with another embodiment of the present invention; 9 Fig. 14 is a top view of the drug-containing unit shown in Fig. 13; Fig. 15 is a side view of the drug-containing unit shown in Fig. 14, 11 with parts shown in section; 12 Fig. 16 is a top view of another electrotransport system in accordance 13 with the present invention; 14 Fig. 17 is a top view of the drug-containing unit of the system shown in Fig. 16; and 16 Fig. 18 is a perspective view showing the coupling of the reusable 17 controller to the drug-containing unit of the system shown in Figs. 16 and 17.

18 19 MODES FOR CARRYING OUT THE INVENTION 21 Fig. 1 is a perspective view of electrotransport device 10 having a 22 reusable electronic controller 12 which is adapted to be coupled to and 23 uncoupled from, drug-containing unit 30. The controller 12 is reusable, 24 it is adapted to be used with a plurality of drug units 30, a series of identical and/or similar drug units 30. On the other hand, drug unit 26 typically has a more limited life and is adapted to be discarded after use, 27 when the drug contained therein has been delivered or has been 28 depleted.

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WO 96/36394 PCTfUS96/06098 9 1 The controller 12 is comprised of a housing 14, typically formed of a 2 molded plastic material. With reference to Fig. 2, there is shown a sectional 3 view of the device 10 with the drug unit 30 coupled to the controller 12.

4 The controller 12 includes a battery 20, e.g. a button cell battery, for powering the circuit board 22. The circuit board 22 is formed in a 6 conventional manner, having conductive traces patterned for interconnecting 7 component(s) 24 thereon. Electrical component(s) 24 control the 8 magnitude, timing, frequency, waveform shape, etc., of the electric current 9 applied by device 10. Although not critical to the invention, controller 12 includes a push button switch 18 which can be used to start operation of 11ii device 10 and a liquid crystal display (LCD) 16 which can display system 12 information such as current level, dosing level, number of doses delivered, 13 elapsed time of current application, battery strength, etc.

14 The drug unit 30 is configured to be removably coupled to the controller 12, with the top of drug unit 30 adjacent to and facing the bottom of 16 the controller 12. The top of drug unit 30 is provided with the male parts of 17 two snap type connectors, the male parts being posts 36 and 38 which 18 extend upwardly from drug unit 30. The bottom of housing 14 is provided with 19 receptacles 26 and 28 (shown in Fig. 2) which are electrically connected to the outputs of the circuit on circuit board 22 by through-board connectors 21 23 and 25, respectively. Receptacle 26 is positioned and sized to receive 22 donor post 36 and receptacle 28 is positioned and sized to receive counter 23 post 38. Receptacles 26, 28 and posts 36, 38 are made from an electrically 24 conductive material a metal such as silver, brass, stainless steel, platinum, gold, nickel, beryllium, copper, etc. or a metal coated polymer, 26 ABS with a silver coating). The donor post 36 is electrically connected to 27 the donor electrode 31, which in turn is electrically connected to the donor 28 reservoir 32 which typically contains a solution of the therapeutic agent 29 a drug salt) to be delivered. The counter post 38 is electrically connected to the counter electrode 33, which in turn is electrically connected

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WO 96/36394 PCT/US96/06098 1 to the counter reservoir 34 which typically contains a solution of a 2 biocompatible electrolyte buffered saline). The electrodes 31 and 33 3 are typically comprised of electrically conductive materials, most preferably a 4 silver silver foil or silver powder loaded polymer) anodic electrode and a silver chloride cathodic electrode. The reservoirs 32 and 34 typically include 6 hydrogel matrices which hold the drug or electrolyte solutions and are 7 adapted to be placed in contact with the body surface skin) of a patient 8 (not shown) when in use. The electrodes 31,33 and the reservoirs 32,34 are 9 isolated from each other by foam member 35. The bottom patient contacting) surface of foam member 35 is preferably coated with a skin 11 contact adhesive. A release liner 39 covers the body contacting surfaces of 12 the two reservoirs 32 and 34 and the adhesive coated surface of foam 13 member 35 before the unit 30 is put in use. The release liner 39 is preferably 14 a silicone coated polyester sheet. The release liner 39 is removed when the device 10 is applied to the skin of a patient (not shown).

16 Thus, the donor post 36 and the receptacle 26 comprise a snap type 17 connector which electrically connects an output of the circuit on circuit board 18 22 to the drug-containing donor electrode 32. Similarly, the counter post 38 19 and the receptacle 28 comprise a snap type connector which electrically connects an output of the circuit on circuit board 22 to the electrolyte 21 containing counter electrode 34. In addition to providing the above described 22 electrically connections, the two snap connectors also provide a separable 23 not permanent) mechanical connection of the drug unit 30 to the 24 controller 12.

The two outputs of the circuit on circuit board 22 have different 26 polarities, one output is positive and is adapted to be connected to the 27 anodic electrode in drug unit 30 whereas the other circuit output is negative 28 and is adapted to be connected to the cathodic electrode in drug unit 29 It is important to ensure that the connections of the two electrodes in drug WO 96/36394 PCT/US96/06098 11 1 unit 30 are connected to the controller outputs of the correct polarity, since if 2 the connections are reversed if the positive circuit output is connected to 3 the cathodic electrode and the negative circuit output is connected to the 4 anodic electrode), little if any drug would be delivered by electrotransport.

The present invention ensures correct polarity connections by making it 6 substantially impossible to make incorrect reversed) polarity connections 7 between the controller 12 and the drug unit 30. As is clearly shown in 8 Figs. 1 and 2, the diameter of post 36 is larger than the diameter of post 38.

9 Similarly, the inside diameter of receptacle 26 is larger than the inside diameter or receptacle 28. Preferably, the inside diameter of receptacle 28 is 11ii smaller than the diameter of post 36 so that it is not possible to insert post 36 12 into receptacle 28.

13 In accordance with this embodiment of the present invention, each of 14 posts 36 and 38 has a different size. Those skilled in the art will appreciate that in addition to the size diameter) of posts 36, 38 being made 16is different, the shape cross-sectional or other shape) of posts 36, 38 17 could be made sufficiently different to ensure only correct polarity connections 18 between controller 12 and drug unit 19 An alternate means for ensuring correct polarity connections between a drug unit having donor and counter electrodes and a controller is illustrated 21 in Fig. 3. Reusable controller 12' is adapted to be separably connected to 22 one or more drug units 40. Drug unit 40 has a donor post 42 which performs 23 a similar function as donor post 36 illustrated in Figs. 1 and 2. However, 24 unlike drug unit 30, drug unit 40 has a receptacle 44 which is electrically connected to the counter electrode (not shown) in the drug unit 26 Receptacle 44 is adapted to engage a post (not shown) extending from the 27 underside of controller 12'. Thus, drug unit 40 contains both a male part 28 post 42) of a first snap connector and a female part receptacle 44) 29 of a second snap connector. The two snap connectors provide both electrical and mechanical coupling of the drug unit 40 to controller 12'. By having a WO 96/36394 PCT/US96/06098 12 1 male connector and a female connector in each of the drug unit 40 and the 2 controller 12', the coupling of the controller 12' to the drug unit 40 can only be 3 accomplished in one way, with the correct polarity connections.

4 Referring now to Fig. 4, there is shown an electrotransport device comprised of a reusable electronic controller 12" and a drug unit 6 Unlike device 10 illustrated in Figs. and 2, the reusable controller 12" has a 7 third snap type receptacle adapted to receive a third post 56 on drug unit 8 Thus, posts 52 and 54 perform substantially the same function as posts 36, 9 38 in device 10. The positioning of the third post 56, as well as the positioning of the receptacle (not shown) for post 56 in the bottom of 11 controller 12", should not be equidistant from posts 52 and 54 assuming that 12 the posts and receptacle are all the same size and shape. By positioning 13 post 56 closer to post 54 than to post 52, there is only one way to connect the 14 drug unit 50 to the controller 12", with correct polarity connections.

An alternative way to ensure correct polarity connections between a 16 controller 62 and a drug unit 80 is illustrated in Figs 5 to 7. Electrotransport 17 device 60 is comprised of a reusable controller which is adapted to be 18 coupled to a plurality of same or similar drug units 80 in succession.

19 The body of the controller 62, shown in section in Fig. 7, is shown as a solid cross section to simplify the drawing. Those skilled in the art will appreciate 21 that controller 62 contains an electrical power source and a current control 22 circuit similar to that illustrated in Fig.2. Controller 62 has two circuit outputs 23 68 and 70 which need to make electrical connection to electrode contacts 24 82 and 84, respectively in order to ensure correct polarity electrical connection of electrodes 88 and 90 to controller 62. Controller 62 includes a 26 clasp 64. The drug unit 80 is adapted to be slid into the space between clasp 27 64 and the body of controller 62. A post 66 engages notch 86 in drug unit 28 when the drug unit 80 is slid into place and helps position drug unit 80 relative 29 to controller 62 so that circuit output 68 touches electrode contact 82 and circuit output 70 contacts electrode contact 84. In addition to the siding _i i:j_ Lii ~i ____illjji~ WO 96/36394 PCT1US96/06098 13 1 engagement of drug unit 80 with controller 62, there is also provided a snap 2 type connector which provides secure, but separable, mechanical connection 3 of drug unit 80 to controller 62. The snap connector is comprised of a 4 receptacle 72 in the body of controller 62 and a post 92 on drug unit The post 92 snaps into receptacle 72 as best shown in Fig. 7.

6 An alternative way to ensure correct polarity connections between a 7 controller 112 and a drug unit 130 is illustrated in Fig. 8. Electrotransport 8 device 110 is comprised of a reusable controller 112 which is adapted to be 9 coupled to a plurality of same or similar drug units 130 in succession.

Controller 112 contains an electrical power source and a current control 11 circuit similar to controller 12 illustrated in Figs. 1 and 2. Controller 112 has 12 two receptacles (not shown in Fig. 8) adapted to engage posts 136 and 138 13 in drug unit 130. Unlike the device illustrated in Figs. 1 and 2, posts 136 and 14 138 have the same size. In order to ensure that the posts 136 and 138 are snapped into the correct receptacles on the underside of controller 112, 16 a projecting member 134 is provided on the surface of drug unit 130 which 17 abuts against the underside of controller 112. As shown in Fig. 8, projecting 18 member 134 has a square shape which engages a square shaped hole 19 (not shown in Fig. 8) on the underside of controller 112. Those skilled in the art will appreciate that projecting member 134 may have any number of 21 different shapes such as triangular, rectangular, circular, half-moon, etc. and 22 should preferably project out a sufficient distance from the surface of drug unit 23 130 to ensure that post 138 cannot engage the incorrect receptacle in 24 controller 112 in the event the patient attempts to couple the drug unit 130 to the controller with incorrect polarity connections. Preferably, the projecting 26 member 134 is provided on a spine member 132 having increased rigidity.

27 It is important that projecting member 134 be positioned on spine 132 at a 28 location other than the midpoint between the two posts 136 and 138 in order 29 to ensure that only one the correct) polarity connection between the drug unit 130 and the controller 112 can be made.

WO 96/36394 PCT/US96/06098 14 1 Referring now to Figs. 9 through 12, there is shown an alternate 2 embodiment of an electrotransport device 210 comprised of a controller 212 3 which is adapted to be coupled to a plurality of same or similar drug units 230 4 in succession. As best shown in Figs. 9 and 10, drug unit 230 has a pair of posts 236, 238 adapted to engage receptacles (not shown) in the underside 6 of controller 212. The posts 236, 238 are preferably provided on a rigid spine 7 member 232. Also provided on spine member 232 is a wedge-shaped 8 projecting member 234. As best shown in Figs. 11 and 12, the controller 212 9 has a wedge-shaped opening 235 with a size and shape which is adapted to mate with the wedge-shaped projecting member 234. The projecting member 11 234 and the opening 235 provide a visual lock and key mechanism which 12 visually guides the user to couple the controller 212 to the drug unit 230 with 13 the correct polarity connections therebetween. If further certainty is required, 14 the controller 212 may be made in a manner wherein the projecting member 234 engages and closes a switch contained in controller 212 thereby closing 16 a circuit pathway which enables the device to deliver electrotransport drive 17 current to the patient. When the projecting member 234 is disengaged from 18 the opening 235, the switch is opened and electrotransport drug delivery is 19 not possible.

Referring now to Figs. 13 through 15, there is shown an 21 electrotransport device 310 comprised of a reusable controller 312 adapted to 22 be coupled to a series of same or similar drug units 330. The drug unit 330 23 has a receptacle 334 which is adapted to accept and engage an end of 24 controller 312. The snap connections are provided in a position which insures that the controller 312 can be electrically coupled to drug unit 330 only when 26 one of the two ends of controller 312 is inserted into receptacle 334.

27 Alternatively, the receptacle 334 can be sized and/or shaped to accept only 28 one of the two ends of controller 312. The selective engagement of controller 29 312 can be accomplished through any number of known means including appropriately varying the size and/or shape of the respective ends of

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WO 96/36394 PCT/US96/06098 1 controller 312 and/or providing some type of appropriate keying mechanism 2 (not shown). In this way, only one end of the controller 312 may be engaged 3 within receptacle 334, thereby ensuring correct polarity connections between 4 the controller 312 and the drug unit 330 by means of the two snap connectors of the kind described hereinbefore.

6 Referring now to Figs. 16 through 18, there is shown another 7 embodiment of the present invention. Like the system shown in Figures 13 8 through 15, electrotransport device 410 is comprised of a controller 412 which 9 is adapted to fit in a single orientation within receptacle 434 on drug unit 430 due to the dissimilarly shaped ends (one end is flat and the other end is 11 rounded) of controller 412 and receptacle 434. By shaping the receptacle 12 434 to "match" the shape of only one of the two ends of controller 412, 13 only one the correct) polarity connection between controller 412 and the 14 drug unit 430 can be made.

While the foregoing detailed description has described several 16 embodiments for ensuring correct polarity coupling of an electrotransport 17 controller to a drug unit having donor and counter electrodes, it is to be 18 understood that the above description is illustrative only and not limiting of the 19 disclosed invention. It will be appreciated that it is possible for one skilled in the art to modify the materials, dimensions, type and shape of the couplers 21 disclosed herein, or to include or exclude various elements, and yet remain 22 within the scope and spirit of this invention. Thus the invention is to be limited 23 only by the following claims.

Claims

1. An electrotransport device for delivering a therapeutic agent through a body surface of a patient, the device including: a therapeutic agent-containing unit including first and second reservoirs and first and second electrodes electrically connected to said first and second reservoirs, wherein at least one of the reservoirs contains the therapeutic agent to be delivered; and a controller having the bipolar electrical power source for providing electric current to the electrodes, the controller having first and second connectors for electrically connecting the first and second poles of the bipolar power source to the first and second electrodes, respectively, wherein the device further includes a coupler which only permits electrical connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit.

2. The device of claim 1 wherein the coupler is a post and receptacle that requires 0000 0:0 15 connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent- 0000 r. containing unit.

3. The device of claim 1 wherein the coupler is a post and receptacle snap coupler that requires connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit.

4. The device of claim 1 wherein the coupler is a square-shaped projecting member -17- and hole that requires connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit.

The device of claim 1 wherein the coupler is a lock-and-key coupler that requires connection between the first electrode and first pole and the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit.

6. The device of claim 1 wherein the coupler is a receptacle that requires connection between the first electrode and first pole and the second electrode and second pole, r respectively, when the controller is mated to the therapeutic agent-containing unit.

7. The device of claim 1 wherein the first pole is positive, the first electrode is an anode, and the therapeutic agent is cationic. 0* S

8. The device of claim 1 wherein the first pole is negative, the first electrode is a cathode, and the therapeutic agent is anionic.

9. The device of claim 1 wherein first and second connectors are male members that snap connect to the first and second poles which are female members.

The device of claim 9 wherein the connectors and poles are constructed from a material selected from the group consisting of metal and carbon.

11. The device of claim 10 wherein the metal is selected from the group consisting of 00 silver and stainless steel.

12. The device of claim 1 wherein the bipolar source is a battery.

13. The device of claim 1 wherein the therapeutic agent-containing unit is adapted to be singularly used.

14. The device of claim 4 wherein the controller is adapted to be electrically connected -18- to successive therapeutic agent-containing units.

A method for using an electrotransport device for delivering therapeutic agent through a body surface of a patient, the device including the steps of: providing a therapeutic agent-containing unit including first and second reservoirs electrically connected to first and second electrodes provided for being electrically connected to first and second poles of a bipolar electrical power source, wherein at least one of the reservoirs contains the therapeutic agent to be delivered; providing a controller having the bipolar electrical power source for providing electric current to the electrodes, the controller having first and second connectors for 10 electrically connecting the first and second poles of the bipolar power source to the first and second electrodes, respectively, wherein the device further includes a coupler which 0* only permits electrical connection between the first electrode and first pole and between the second electrode and second pole, respectively, when the controller is mated to the therapeutic agent-containing unit; 15 electrically and mechanically connecting the therapeutic agent-containing unit and S. the controller; contacting the therapeutic agent-containing unit with the body surface of a patient; and o: activating the electrical power source delivering the therapeutic agent to the body surface.

16. The method of claim 15 further including the step of providing a push button switch and a liquid crystal display electrically connected to the bipolar electrical power source.

17. The method of claim 15 wherein the therapeutic agent is a drug salt. S17. The method of claim 15 wherein the therapeutic agent is a drug salt. -19-

18. The method of claim 15 wherein the first and second electrodes are constructed from silver and silver chloride, respectively.

19. The method of claim 15 further including the step of providing a hydrogel matrice in the first and second reservoirs.

20. The method of claim 15 further including the step of providing a foam member coated with a skin contact adhesive to insulate the first and second electrodes.

21. The method of claim 20 further including the step of providing a release liner constructed from silicone coated polyester sheet and covering a portion of the first and C second reservoirs and the foam member. 10

22. The method of claim 15 wherein the bipolar electrical power source is a battery.

S23. The method of claim 15 wherein the electrotransport device is adapted to be singly S° used.

24. The method of claim 15 wherein the controller is adapted to be used with a plurality of successive therapeutic agent-containing units. 15

25. An electrotransport device for delivering a therapeutic agent through a body surface of a patient substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings.

26. A method for using an electrotransport device for delivering a therapeutic agent CCC through a body surface of a patient substantially as herein described with reference to 00 any one of the embodiments of the invention illustrated in the accompanying drawings. DATED this 27th Day of October, 1999 ALZA CORPORATION Attorney: STUART M. SMITH Fellow Institute of Patent Attorneys of Australia 25 of BALDWIN SHELSTON WATERS