Patent ID: 6328996
Filing Date: 2001-12-11
Classification: A61K,Y10S

Abstract:
A drug delivery composition capable of selective release of said drug into a preselected physiological environment, comprising:(1) a synthetic bioelastic polypetide polymer comprising repeating elastomeric units selected from the group consisting of bioelastic pentapeptides, tetrapeptides, and nonapeptides, wherein said repeating units comprise amino acid residues selected from the group consisting of hydrophobic amino acid and glycine residues and wherein said repeating units exit in a conformation having a .beta.-turn; and(2) a drug retained by said polymer;wherein said polymer is selected to be in a first contraction state, selected from the group consisting of contracted and relaxed bioelastomer states, when contacted with a physiological environment present in a human or animal to whom said composition is administered and wherein said polymer contains a reactive functional group that undergoes a reaction, either in the presence of said physiological environment or when said polymer is transported by a natural process in said human or animal to a location having a different physiological environment, to produce a second functional group, wherein the presence of said second functional group in said polymer causes said polymer to switch to the other of said contraction sites, thereby making said drug available for release from said composition into said preselected physiological environment.