Transdermal Electrotransport Delivery Device Including an Antimicrobial Compatible Reservoir Composition

Abstract

A transdermal electrotransport drug delivery device having an anode, a cathode and a source of electrical power electrically connected to the anode and the cathode. At least one of the anode and the cathode includes an electrode and a reservoir comprised of a housing composed of a polymeric material and an aqueous medium in contact with the housing. The aqueous medium includes (i) a drug or an electrolyte salt or a mixture thereof, (ii) propylene glycol, and (iii) an antimicrobial agent in an amount sufficient to inhibit microbial growth in the aqueous medium. The propylene glycol prevents the antimicrobial agent from being adsorbed by other materials used in the construction of the delivery device. A process for preparing a transdermal electrotransport drug delivery device is also provided.

1 . An aqueous medium for use in a transdermal electrotransport delivery or sampling device reservoir, said reservoir contained in a polymeric reservoir housing, said aqueous medium comprised of. (i) a drug, an electrolyte salt or a mixture thereof, (ii) propylene glycol, and (iii) an antimicrobial agent in an amount sufficient to inhibit microbial growth in said aqueous medium; wherein said propylene glycol is present in an amount which renders said antimicrobial agent compatible with said device. 
   
   
       2 . The aqueous medium of  claim 1 , wherein said aqueous medium has a pH in the range of approximately 4.0 to 9.0. 
   
   
       3 . The aqueous medium of  claim 2 , wherein said aqueous medium has a pH in the range of approximately 5.0 to 8.0. 
   
   
       4 . The aqueous medium of  claim 1 , wherein said aqueous medium further comprises a buffer. 
   
   
       5 . The aqueous medium of  claim 1 , wherein said polymeric housing material is selected from the group consisting of polyethylene terephthalate, polyethylene terephthalate modified with cyclohexane dimethylol, polypropylene, polyethylene, polyethylene copolymers, and mixtures thereof. 
   
   
       6 . The aqueous medium of  claim 1 , wherein said drug comprises fentanyl in a form that can be delivered when current flows from said source of electric power. 
   
   
       7 . The aqueous medium of  claim 1 , wherein said antimicrobial agent is selected from the group consisting of methylparaben, ethylparaben and propylparaben, propyl gallate, butylated hydroxyanisole (BHA), butylated hydroxytoluene, t-butyl-hydroquinone, chloroxylenol, chlorohexidine, dichlorobenzyl alcohol, dehydroacetic acid, hexetidine and triclosan. 
   
   
       8 . The aqueous medium of  claim 7 , wherein said antimicrobial agent comprises a paraben. 
   
   
       9 . The aqueous medium of  claim 9 , wherein said antimicrobial agent is present in the range of approximately 0.005% 2% by weight of said aqueous medium. 
   
   
       10 . The aqueous medium of  claim 9 , wherein said antimicrobial agent is present in the range of approximately 0.01% to 1% by weight of said aqueous medium. 
   
   
       11 . The aqueous medium of  claim 1 , wherein said propylene glycol is present in range of approximately 5% to 50% by weight of said aqueous medium. 
   
   
       12 . The aqueous medium of  claim 11 , wherein said propylene glycol is present in a range of approximately 5% to 30% by weight of said aqueous medium.