compositions useful for carrying physiologically active agents such as therapeutic agents through skin and other body membranes comprising the agent and an effective , non - toxic amount of a compound having the structural formula ## str1 ## wherein r &# 39 ; is h or a lower alkyl group , m is 3 - 7 , n is 0 - 17 and r is -- ch 3 , phenyl or substituted phenyl or ## str2 ## with the proviso that if m is 3 and r is -- ch 3 , then n is not 0 - 6 .