Methadone hydrochloride is widely used in drug treatment of heroin addicts and effectively relieves the craving for heroin. However, methadone is itself addictive and a drug of abuse. As a result, diversion of methadone to the black market by patients is a serious problem and the drug cannot usually be given to patients for self-medication. There is reason to believe that methadone free base would be sufficiently skin permeable to allow administration as a transdermal patch, especially if the drug is administered with a skin permeation enhancer such as ethanol or propanol. We propose to develop such a system. Because methadone in a transdermal patch compounded with unpalatable excipient would not be open to abuse, this approach could allow innovations in drug treatment programs to be attempted. In the proposed Phase I program, the permeability of skin to methadone free base with and without skin permeation enhancers would be determined. If these results are sufficiently encouraging, transdermal devices would be developed in Phase II program and a collaborative effort with a clinical researcher leading to the submission of an IND undertaken.
