Disposable dosage unit for iontophoresis-facilitated transdermal delivery, related devices and processes

Claim 1

A pharmaceutical dosage unit adapted to be removably assembled with a reservoir electrode of a transdermal periodic iontotherapeutic system, said dosage unit to be used in electrical contact with intact skin to be iontotherapeutically treated to administer transdermally a systemically effective dose amount of an effective and transdermally absorbable amount of an ionized pharmaceutical; said dosage unit comprising solution of said ionized pharmaceutical dispersed therein having an iontotherapeutically effective and physiologically acceptable pH at least about one pH unit lower or higher than the pKa or isoelectric point of said pharmaceutical; said unit dose adapted to permit said pharmaceutical to be released upon application to the reservoir electrode of an effective pulsed DC current; said dosage unit having the following elements: a. a dimensionally stable hydrophilic gel polymer first layer which comprises a hydrophilic polymer which has dispersed therein an ionic exchange resin which is effective in removing the ions generated by the electrode during the operation of the iontotherapeutic system; b. a permselective membrane is intimately adhered to the top surface of the hydrophilic polymer layer which has a pores size sufficiently small to prevent any substantial passage of the pharmaceutical through the membrane; c. a hydrophilic gel polymer second layer intimately adhered to the top surface of the permselective membrane and having dispersed therein an effective dose amount of an ionized pharmaceutical solution, said solution having a pH at least one pH unit below or above the pKa or isoelectric point of the pharmaceutical; d. a thin fabric disc intimately adhered to the hydrophilic gel polymer second layer; and e. an adhesive polymer third layer being in intimate contact with the thin fabric disc and providing intimate contact with the skin of a subject being treated; said dosage unit adapted to be received by the pharmaceutical reservoir electrode and to make electrical contact with the electrical terminus of said pharmaceutical reservoir electrode.