Electrokinetic drug delivery apparatus

Abstract

A portable iontophoresis apparatus for facilitating delivery of medication across the cutaneous membrane into adjacent underlying tissues and blood vessels. The apparatus employs a modular, detachable non-reusable medicament-containing applicator electrode which is adapted to attach to a base assembly. The apparatus is designed to be hand-held and includes a circumferential tactile electrode band on the base assembly which provides electrical connection between the skin of the user's hand and one pole of a bipolar power source housed within the base assembly. The opposing pole of the power source is connected to the applicator electrode. The user's body completes the electrical circuit between the applicator and tactile electrodes. A method for using the device for the treatment of Herpes simplex infection and related viral infections which produce similar cutaneous lesions is presented. The apparatus, when used in accordance with the method described herein, demonstrated >90% treatment efficacy in clinical trials.

What I claim is:  
     
       1. An iontophoretic drug delivery device for personal use for self administering a medicament into a person's skin, said device comprising a base assembly and a detachable applicator electrode wherein said base assembly comprises: 
       (a) a case having an elongate, substantially cylindrical outer surface having a size and shape adapted to be comfortably grasped within a person's hand and wherein at least a portion of said outer surface is a tactile electrode formed of as electrically conductive material;  
       (b) a bipolar electrical power means having a first pole and a second pole; said electrical power means being enclosed within said case and wherein said first pole is in electrical communication with said tactile electrode;  
       and wherein said applicator electrode comprises a porous matrix portion, a module containing a unit dose of medicament, an electrically conductive working electrode and attachment means adapted for releasably attaching said application electrode to said base assembly to provide electrical connection between said working electrode and said second pole of said electrical power means and wherein said iontophoretic delivery device is operable for releasing said medicament to permeate said porous matrix portion and delivering said medicament from said porous matrix portion to a portion of the person's skin in contact with matrix portion of said applicator electrode.  
     
     
       2. The device in  claim 1  wherein said unit dose of medicament is encapsulated within a rupturable reservoir. 
     
     
       3. The device in  claim 2  wherein said rupturable reservoir further contains a visualizing agent which is released when said reservoir is ruptured thereafter providing a visual signal indicating the release of medicament. 
     
     
       4. The device of  claim 2  wherein the porous matrix portion is selected from the group consisting of polyethylene, paper, cotton, polytetrafluoroethylene, open-celled polyurethane, open-celled silicone and ceramic. 
     
     
       5. The device of  claim 3  wherein the porous matrix portion is selected from the group consisting of polyethylene, paper, cotton, polytetrafluoroethylene, open-celled polyurethane, open-celled silicone and ceramic. 
     
     
       6. An electrokinetic drug delivery device for personal use for self- administering a medicament into a person's skin, said device comprising a base assembly and a detachable applicator electrode wherein said base assembly comprises:    
       ( a )  a case having an elongate, substantially cylindrical outer surface having a size and shape adapted to be comfortably grasped within a person's hand and wherein at least a portion of said outer surface includes a tactile electrode formed of an electrically conductive material;    
       ( b )  a bipolar electrical power means having a first pole and a second pole, said electrical power means being enclosed within said case and wherein said first pole is in electrical communication with said tactile electrode; and    
       ( c )  a current driver and a voltage multiplier in electrical contact with said second pole;    
       
         and wherein said applicator electrode includes a porous matrix portion, a module containing a unit dose of medicament for release into and permeation of the porous matrix portion, an electrically conductive working electrode and attachment means adapted for releasably attaching said applicator electrode to said base assembly to provide electrical connection between said working electrode and said second pole of said electrical power means through said current driver and voltage multiplier and wherein, upon release of the medicament and permeation of the porous matrix portion, said electrokinetic delivery device being operable to electrokinetically deliver said medicament from said porous matrix portion to a portion of the person's skin in contact with the porous matrix portion of said applicator electrode. 
       
     
     
       7. A device according to  claim 6  wherein said unit dose of medicament is encapsulated within said module, said module comprising a rupturable reservoir. 
     
     
       8. A device according to  claim 7  wherein said rupturable reservoir further contains a visualizing agent which is released when said reservoir is ruptured to provide a visual signal indicating the release of medicament. 
     
     
       9. A device according to  claim 8  wherein the porous matrix portion is elected from the group consisting of polyethylene, paper, cotton, polytetrafluoroethylene, open- celled polyurethane, open - celled silicone and ceramic.   
     
     
       10. A device according to  claim 7  wherein the porous matrix portion is selected from the group consisting of polyethylene, paper, cotton, polytetrafluoroethylene, open- celled polyurethane, open - celled silicone and ceramic.   
     
     
       11. A device according to  claim 6  including a visualizing agent carried by said device for indicating one- time usage of the device.   
     
     
       12. An electrokinetic delivery device for personal use and self- administration of a medicament to an individual's treatment site, comprising:    
       
         a base assembly having a portion thereof shaped for manual manipulation by a hand of the individual, and a tactile electrode formed of electrically conductive material and exposed on said base assembly for electrical contact with the individual's hand;  
       
         a self - contained power source within said base assembly and in electrical contact with said tactile electrode;    
       
         an applicator electrode;  
       
       
         attachment means for releasably attaching the applicator electrode to the base assembly, said applicator electrode including a porous matrix and a unit dose of an electrokinetically transportable medicament encapsulated in a rupturable reservoir, said porous matrix lying in electrical contact with said power source and having a surface for contact with the individual's treatment site;  
       
         a current driver and a voltage multiplier carried by said base assembly and electrically coupled to said power source and providing a defined current and voltage output at said applicator electrode, said current driver limiting the current available to the applicator electrode within a range of  0 . 05 - 0 . 6  milliamps per cm   2 ;  
       
         said device being operable, upon rupture of said reservoir, to release the medicament to permeate the porous matrix and electrokinetically transport said medicament from said applicator electrode to the individual's treatment site in contact with said surface in response to completion of an electrical circuit with said power source via at least a portion of the individual's hand through said tactile electrode and said applicator electrode surface and the individual's treatment site. 
       
     
     
       13. A device according to  claim 12  including an indicator affording a visual indication of medicament release into the porous material. 
     
     
       14. A device according to  claim 12  including means for preventing reuse of the applicator electrode. 
     
     
       15. A device according to  claim 12  wherein said current driver limits the current available to the applicator electrode to less than  0 . 6  milliamp per cm 2 . 
     
     
       16. A device according to  claim 12  wherein said applicator electrode comprises a disposable applicator electrode. 
     
     
       17. A device according to  claim 12  wherein said base assembly is elongated and has opposite ends, said tactile electrode being exposed through said shaped portion, said applicator electrode being carried by said base assembly adjacent one of said ends thereof and being exposed therefrom for contact with the individual's treatment site. 
     
     
       18. A device according to  claim 17  wherein said shaped portion comprises a cylindrical surface having said tactile electrode exposed along said cylindrical surface. 
     
     
       19. A device according to  claim 12  including an indicator affording a visual indication of medicament release into the porous material, said base assembly being elongated and having opposite ends, said tactile electrode being exposed through said shaped portion, said applicator electrode being carried by said base assembly adjacent one of said ends thereof and being exposed therefrom for contact with the individual's treatment site. 
     
     
       20. A device according to  claim 12  including means for preventing reuse of the applicator electrode, said base assembly being elongated and having opposite ends, said tactile electrode being exposed through said shaped portion, said applicator electrode being carried said base assembly adjacent one of said ends thereof and being exposed therefrom for contact with the individual's treatment site. 
     
     
       21. An electrokinetic delivery device for personal use and self- administration of a medicament to an individual's treatment site, comprising:    
       
         a base assembly having a portion thereof shaped for manual manipulation by a hand of the individual, and a tactile electrode formed of electrically conductive material and exposed on said base assembly for electrical contact with the individual's hand;  
       
         a self - contained power source within said base assembly and in electrical contact with said tactile electrode;    
       
         an applicator electrode including a porous matrix for interposition between said base assembly and the treatment site and a unit dose of an electrokinetically transportable medicament encapsulated in a rupturable reservoir, said porous matrix lying in electrical contact with said power source, said porous matrix having a surface for contact with the individual's treatment site;  
       
         a current driver and a voltage multiplier carried by said base assembly and electrically coupled to said power source and providing a defined current and voltage output at said applicator electrode, said current driver limiting the current available to the applicator electrode within a range of  0 . 05 - 0 . 6  milliamps per cm   2 ,  
       
         said device being operable, upon rupture of said reservoir, to release the medicament to permeate the porous matrix and electrokinetically transport said medicament from said applicator electrode to the individual's treatment site in contact with said surface in response to completion of an electrical circuit with said power source via at least a portion of the individual's hand through said tactile electrode and said applicator electrode surface and the individual's treatment site. 
       
     
     
       22. A device according to  claim 21  including an indicator affording a visual indication of medicament release into the porous material. 
     
     
       23. A device according to  claim 21  including means for preventing reuse of the applicator electrode. 
     
     
       24. A device according to  claim 21  wherein said applicator electrode comprises a disposable applicator electrode, said base assembly being elongated and having opposite ends, said tactile electrode being exposed through said shaped portion, said applicator electrode being located adjacent one of said ends thereof and exposed therefrom for contact with the individual's treatment site. 
     
     
       25. A device according to  claim 24  wherein said shaped portion comprises a cylindrical surface having said tactile electrode exposed along said cylindrical surface. 
     
     
       26. A device according to  claim 24  including an indicator affording a visual indication of medicament release into the porous material. 
     
     
       27. A device according to  claim 24  including means for preventing reuse of the applicator electrode. 
     
     
       28. A device according to  claim 27  including an indicator affording a visual indication of medicament release into the porous material. 
     
     
       29. A device according to  claim 21  including a visualizing agent carried by said device for indicating one- time usage of the device.