Claims for Patent: 4,060,084

Summary for Patent: 4,060,084

Title:	Method and therapeutic system for providing chemotherapy transdermally
Abstract:	Method and therapeutic system in the form of a bandage for providing chemotherapy transdermally by administering certain drugs to unbroken skin in an initial priming dose that quickly brings the systemic concentration of drug to a therapeutic level, followed by a substantially constant dosage that holds said level. The bandage is a four-layer laminate of, from the top: a protective backing; a drug reservoir lamina that is the source of the constant dosage; a microporous membrane that controls the constant dosage rate; and an adhesive layer that is the source of the priming dose and the means by which the bandage is attached to the skin.
Inventor(s):	Chandrasekaran; Santosh Kumar (Palo Alto, CA), Urquhart; John (Palo Alto, CA), Shaw; Jane Elizabeth (Atherton, CA)
Assignee:	Alza Corporation (Palo Alto, CA)
Application Number:	05/763,314
Patent Claims:	1. Method for providing chemotherapy transdermally comprising: a. administering a priming dose of a drug to a predetermined area of unbroken skin, said drug being (i) indicated systemically for said therapy at a predetermined systemic concentration and (ii) capable of permeating through said predetermined area of skin at a rate that produces a steady-state systemic concentration of the drug at least about equal to said predetermined systemic concentration, with the proviso that the ratio of said rate on an hourly basis to the quantity of drug immobilized by said predetermined area of skin is less than about 10, wherein the quantity of the drug in the priming dose is at least a substantial portion of said quantity of drug immobilized by said predetermined area of skin; and b. thereafter administering the drug to said predetermined area of skin continuously at a rate that maintains the steady-state systemic concentration of the drug at about said predetermined systemic concentration. 2. The method of claim 1 wherein the skin is located at the mastoidal area. 3. The method of claim 1 wherein the drug is capable of permeating through said predetermined area of skin at a rate that produces a steady-state systemic concentration of the drug substantially greater than said predetermined systemic concentration. 4. The method of claim 1 wherein the quantity of drug in the priming dose is approximately equal to said quantity of drug immobilized by said predetermined area of skin. 5. The method of claim 1 wherein the skin is located at the mastoidal area, the drug is capable of permeating through said predetermined area of skin at a rate that produces a steady-state systemic concentration of the drug substantially greater than said predetermined systemic concentration, and the quantity of drug in the priming dose is approximately equal to said quantity of drug immobilized by said predetermined area of skin. 6. The method of claim 1 wherein said ratio is less than about 4. 7. The method of claim 1 wherein said predetermined area of skin is not greater than about 10 cm.sup.2. 8. Therapeutic system in the form of a bandage for providing chemotherapy transdermally for a predetermined prolonged time period comprising a sandwich type laminate of: a. a drug reservoir lamina comprising: i. a drug that is: indicated systemically for said therapy at a predetermined systemic concentration; and is capable of permeating through a predetermined area of unbroken skin at a rate that produces a steady-state concentration of the drug at least about equal to said predetermined systemic concentration, with the proviso that the ratio of said rate on an hourly basis to the quantity of drug immobilized by the predetermined area of skin is less than about 10, with the amount of the drug in the drug reservoir lamina being at least equal to the amount of drug calculated by multiplying the rate of drug permeation through said predetermined area of unbroken skin that produces a steady-state systemic concentration approximately equal to said predetermined systemic concentration times the predetermined prolonged time period; and ii. a carrier that is permeable to said drug; b. a backing lamina that is substantially impermeable to the drug, one face of which forms the top of the bandage and the opposite face of which is adjacent to the top face of the drug reservoir lamina; c. a microporous membrane lamina adjacent to the bottom face of the drug reservoir lamina through which the drug is released from the reservoir lamina after the bandage is affixed to said predetermined area of skin at approximately said rate that produces a steady-state systemic concentration approximately equal to said predetermined systemic concentration; and d. a contact adhesive lamina adjacent and below the microporous membrane lamina by which the bandage is affixed to the skin comprising: i. a contact adhesive that is permeable to the drug; and ii a priming dose of said drug, the quantity of drug in said priming dose being at least a substantial portion of the quantity of drug immobilized by said predetermined area of skin. 9. The therapeutic system of claim 8 wherein the quantity of drug in the priming dose is approximately equal to the quantity of drug immobilized by said predetermined area of skin. 10. The therapeutic system of claim 8 wherein said ratio is less than about 4.