Claims for Patent: 6,881,208

Summary for Patent: 6,881,208

Title:	Method and device for transdermal electrotransport delivery of fentanyl and sufentanil
Abstract:	The invention provides an improved electrotransport drug delivery system for analgesic drugs, namely fentanyl and sufentanil. The fentanyl/sufentanil is provided as a water soluble salt (eg, fentanyl hydrochloride) dispersed in a hydrogel formulation for use in an electrotransport device (10). In accordance with one aspect of the invention, the concentration of fentanyl/sufentanil in the donor reservoir (26) solution is above a predetermined minimum concentration, whereby the transdermal electrotransport flux of fentanyl/sufentanil is maintained independent of the concentration of fentanyl/sufentanil in solution. In accordance with a second aspect of the present invention, the donor reservoir (26) of the electrotransport delivery device (10) is comprised of silver and the donor reservoir (26) contains a predetermined "excess" loading of fentanyl/sufentanil halide to prevent silver ion migration with attendant skin discoloration. In accordance with a third aspect of the present invention, a transdermal electrotransport delivered dose of fentanyl/sufentanil is provided which is sufficient to induce analgesia in (eg, adult) human patients suffering from moderate-to-severe pain associated with major surgical procedures.
Inventor(s):	Phipps; Joseph B. (Maple Grove, MN), Southam; Mary (Portola Valley, CA), Bernstein; Keith J. (Somerville, NJ), Noorduin; Henk (Bergen op Zoom 4615 HM, NL)
Assignee:
Application Number:	08/465,492
Patent Claims:	1. A method for delivering an active agent through a body surface by electrotransport comprising the steps of: a) providing an electrotransport delivery device having a silver anodic donor electrode, a cathodic counter electrode, and a donor reservoir containing a loading amount of the analgesic drug in electrical contact with the donor electrode, wherein the donor reservoir is substantially free of sources of halide other than the selected analgesic drug halide salt, the device adapted to deliver a predetermined maximum total amount of analgesic drug over a period of time, the loading amount being at loan about two times the predetermined maximum total amount to prevent transient epidermal discoloration; and b) delivering only up to the maximum total amount of the analgesic drug; wherein the analgesic drug is selected from the group consisting of fentanyl halide salts and sufentanil halide salts thereby avoiding transient epidermal discoloration. 2. The method of claim 1, wherein the donor reservoir comprises a hydrogel containing an aqueous fentanyl salt solution, and further comprising the step of maintaining the solution fentanyl concentration above 6 mg/mL in the hydrogel. 3. The method of claim 1, wherein the body surface is intact skin and the period of time is at least 6 hours. 4. The method of claim 1, wherein the body surface is intact human skin. 5. The method of claim 1, wherein the delivery of the analgesic drug through the body surface is substantially proportional to a level of current applied by the delivery device during the iontophoretic drug delivery. 6. The method of claim 5, wherein the level of current applied by the delivery device ranges between about 150 .mu.A to about 240 .mu.A. 7. The method of claim 5, wherein the level of current applied by the delivery device ranges between about 150 .mu.A to about 190 .mu.A. 8. The method of claim 5, wherein the level of current applied by the delivery device ranges between about 190 .mu.A to about 240 .mu.A. 9. The method of claim 1; wherein the step of delivering only up to a maximum total amount of the analgesic drug comprises delivering multiple predetermined dose amounts. 10. The method of claim 9, wherein the step of delivering a predetermined dose amount comprises applying a level of current for a delivery interval of up to about 20 minutes. 11. The method of claim 10, wherein the step of delivering a predetermined dose amount comprises applying a level of current for a delivery interval of about 8 to about 12 minutes. 12. The method of claim 9, wherein delivering multiple predetermined dose amounts comprises delivering about 10 to about 100 dose amounts. 13. The method of claim 12, wherein the predetermined dose amount is about 20 to 60 .mu.g fentanyl halide. 14. The method of claim 13, wherein the predetermined dose amount is about 40 .mu.g fentanyl halide. 15. The method of claim 9, wherein delivering multiple predetermined dose amounts comprises delivering about 20 to about 80 dose amounts. 16. The method of claim 9, wherein the step of delivering multiple predetermined dose amounts comprises delivering the dose amounts over at least about 6 hours. 17. The method of claim 1, wherein the analgesic drug comprises sufentanil HCl and the loading amount is at least about 4 times greater than the maximum total amount. 18. The method of claim 1, wherein the donor reservoir bas a weight on a hydrated basis of about 0.5 g to 0.8 g and is loaded with at least about 9 mg of fentanyl hydrochloride. 19. The method of claim 1, further comprising the step of preventing transient epidermal discoloration by maintaining a concentration of analgesic drug in the drug reservoir at least equal to the maximum total amount of the analgesic drug. 20. A method for transdermally delivering an active agent by electrotransport comprising the steps of: a) providing an electrotransport delivery device having a silver anodic donor electrode, a cathodic counter electrode, and a donor reservoir containing a loading amount of the analgesic drug in electrical contact with the donor electrode, wherein the donor reservoir comprises a hydrogel containing an aqueous fentanyl salt solution that has a weight on a hydrated basis of about 0.5 g to 0.8 g, is loaded with at least about 9 mg of fentanyl hydrochloride and is substantially free of sources of halide other than the drum halide salt the device adapted to deliver a predetermined maximum total amount of analgesic drug over a period of time, the predetermined maximum total amount being at most about half the loading mount to prevent transient epidermal discoloration by silver; b) delivering only up to the maximum total amount of the analgesic drug by delivering about 10 to about 100 predetermined dose amounts, wherein the predetermined dose amount comprises about 20 to 60 .mu.g fentanyl halide delivered by applying a current of about 150 .mu.A to about 240 .mu.A for a delivery interval of about 8 to about 12 minutes; c) maintaining the solution fentanyl concentration above 6 mg/mL in the hydrogel. 21. A method for transdermally delivering an active agent by electrotransport comprising the steps of: a) providing an electrotransport delivery device having a silver anodic donor electrode, a cathodic counter electrode, and a donor reservoir containing a loading amount of the analgesic drug in electrical contact with the donor electrode, wherein the donor reservoir comprises a hydrogel containing an aqueous sufentanil salt solution and is substantially free of sources of halide other than ec drug halide salt, the device adapted to deliver a predetermined maximum total amount of analgesic drug over a period of time, the loading amount being at least about four times greater than the predetermined maximum total amount; and b) delivering only up to the maximum total amount of the analgesic drug by delivering about 10 to about 100 predetermined dose amounts, wherein the predetermined dose amount comprises about 4 to 5.5 .mu.g sufentanil halide delivered by applying a current of about 150 .mu.A to about 240 .mu.A for a delivery interval of up to about 20 minutes; wherein the drug reservoir prior to delivery has a loading amount of the analgesic drug that is at least about four times greater than the maximum total amount to prevent transient epidermal discoloration.