| abstract |
A composition comprising a flexible backing for a transdermal drug preparation with a water vapor transmission rate about equal to or in excess of that of ethylene vinyl alcohol copolymer, namely equal to or in excess of, at one mil thickness, of about 2 to 4 grams and more preferably in excess of 6 grams per 24 hours per 100 square inches at 40° C and 90% relative humidity and an oxygen transmission rate equal to or less than ethylene vinyl alcohol copolymer, namely at one mil thickness equal to or less than about 0.01 to 0.1 cubic centimeters per 100 square inches measured over 24 hours at 1 atmospheric pressure, 20 ° C and 65% relative humidity. |