Claims for Patent: 3,996,934

Summary for Patent: 3,996,934

Title:	Medical bandage
Abstract:	A bandage for continuously administering controlled quantities of systemically active drugs through the skin or mucosa is disclosed. This bandage has a backing member which defines one of its face surfaces and at least one reservoir containing the systemically active drug formulation which defines the other face surface. The reservoir can be a distinct layer of the bandage or can be a plurality of microcapsules distributed throughout a matrix. The material used to form the reservoir is drug release rate controlling and for a prolonged period continuously meters a controlled and predetermined flow of drug from the reservoir to the skin or mucosa of a patient.
Inventor(s):	Zaffaroni; Alejandro (Atherton, CA)
Assignee:	Alza Corporation (Palo Alto, CA)
Application Number:	05/169,975
Patent Claims:	1. A medical bandage for use in the continuous administration to circulation of controlled quantities of systemically active drugs by absorption through the external body skin or mucosa, said bandage being comprised of a laminate of: (1) a backing member defining one face surface of a bandage; bearing (2) a discrete middle reservoir containing a drug confined therein; the reservoir being formed of a material permeable to passage of drug; and wherein one or more drug release rate controlling membranes are laminated to the surface of the reservoir so as to define the other face surface of the bandage to continuously meter the flow of a therapeutically effective amount of drug to the skin or mucosa of the patient at a predetermined rate over a period of time; and (3) means to secure said bandage to the patient. 2. The bandage as defined by claim 1 wherein said reservoir is laminated to said backing member (1). 3. The bandage as defined by claim 2 wherein the reservoir layer is comprised of a walled container having an interior chamber containing the systemically active drug formulation. 4. The bandage as defined by claim 3 wherein only that portion of the walled container which is adapted to be brought contiguous with the skin or mucosa is formed from the drug release rate controlling material. 5. The bandage as defined by claim 2 wherein the reservoir layer is comprised of a matrix of the drug release rate controlling wall material, said matrix having the systemically active drug formulation distributed therethrough. 6. The bandage as defined by claim 2 wherein the wall member comprising the reservoir layer consists of drug release rate controlling material. 7. The bandage as defined by claim 2 wherein one outer surface of the wall member comprising the reservoir layer also defines the said backing member (1). 8. The bandage as defined by claim 1 wherein said reservoir comprises a plurality of discrete microcapsules distributed throughout a matrix. 9. The bandage as defined by claim 8 wherein each of said microcapsules is comprised of systemically active drug formulation microencapsulated with the said drug release rate controlling wall material. 10. The bandage as defined by claim 8 wherein each of said microcapsules is comprised of a matrix of the drug release rate controlling wall material, said matrix having the systemically active drug formulation distributed therethrough. 11. The bandage as defined by claim 8 wherein the ratio of drug release rate from the material forming the microcapsule to the drug release rate from the material forming the matrix is from 1:2 to 1:100. 12. The bandage as defined by claim 8 wherein the body contacting face surface of the bandage has an area of from about 0.5 to 400 square centimeters. 13. The bandage as defined by claim 1 wherein the systemically active formulation is soluble in the drug release rate controlling material. 14. The bandage as defined by claim 1 wherein the drug formulation comprises a pharmacologically acceptable solvent. 15. The bandage as defined by claim 1 wherein said drug release rate controlling material is silicone rubber. 16. The bandage as defined by claim 1 wherein said drug release rate controlling material is a hydrophilic polymer of an ester of an olefinic acid. 17. The bandage as defined by claim 1 wherein the reservoir is a container having the active agent confined therein. 18. The bandage as defined by claim 1 wherein the reservoir is a solid or microporous matrix having the active agent dispersed therein. 19. The bandage as defined by claim 1 wherein the rate controlling material is microporous and is filled with a medium to permit controlled diffusion of the drug from the reservoir. 20. The bandage as defined by claim 1 wherein the rate controlling membrane material is microporous and is filled with a medium to permit controlled diffusion of the drug from the reservoir. 21. The bandage as defined by claim 1 wherein the means to secure the bandage to a patient comprises a pair of straps connected to opposite ends of the bandage.