The present invention provides bioerodable constructs for controlled
release of bioactive materials. In a preferred mode, the constructs may be
utilized adjacent to a biological surface. The constructs are based on a
blend of two or more poly(ester-amide) polymers (PEA). Such polymers may
be prepared by polymerization of a diol (D), a dicarboxylic acid (C) and
an alpha-amino acid (A) through ester and amide links in the form
(DACA).sub.n. An example of a (DACA).sub.n polymer is shown below in
formula II. Suitable amino acids include any natural or synthetic
alpha-amino acid, preferably neutral amino acids.
