Methods for the manufacture of medicinal compositions are described. A
method for the manufacture of a medicinal composition according to the
invention comprises: (a) Providing a biocompatible polymer of the general
formula --[O--R.sup.1--C(O)].sub.n-- wherein: "R.sup.1" is a linear,
branched, or cyclic organic group, "n" is at least three, (b) Acylating
the biocompatible polymer to provide an acylated biocompatible polymer
and a mixed anhydride; (c) Reacting the mixed anhydride with a
nucleophile to provide an acylated biocompatible polymer with a terminal
carboxylic acid derivative capable of being chemically converted to an
acid in the absence of water, (d) Converting the terminal carboxylic acid
derivative to an acylated biocompatible polymer with a terminal
carboxylic acid; and (e) Combining the acylated biocompatible polymer
with a drug to provide the medicinal composition.