CONTROLLED RELEASE OF ACTIVES IN SKIN

摘要

Topical compositions are provided in which active compounds for topical d elivery through the stratum corneum are complexed with nanospheres of a trib lock 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 differ ent 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 hyd rogen and straight and branched alkyl, alkoxy, alkylaryl and alkoxyaryl grou ps containing up to 18 carbon atoms; and R is selected from a bond or straig ht and branched alkyl, alkoxy, alkylaryl and alkoxyaryl groups containing up to 18 carbon atoms.