Topical compositions are provided in which active compounds for topical delivery through the stratum corneum are complexed with nanospheres of a triblock copolymer having an A-B-A structure wherein each A end block is a water-soluble, hydrophilic and non-toxic polymer or oligomer； and the hydrophobic middle B block is a hydrophobic polymer or oligomer with the same or different repeating units having the structure according to formula:(I) wherein X is - C- R - C - or - C -； Z is between 2 and about 100, inclusive； R1 is CH=CH or (CH2)" wherein n is from 0 to 18, inclusive； R2 is selected from hydrogen and straight and branched alkyl, alkoxy, alkylaryl and alkoxyaryl groups containing up to 18 carbon atoms； and R is selected from a bond or straight and branched alkyl, alkoxy, alkylaryl and alkoxyaryl groups containing up to 18 carbon atoms.
