Systems for the controlled release of macromolecules

A therapeutic system for the continuous and controlled administration of macromolecules, said system being in the form of a body which is sized and shaped for placement in the environment of use, comprising a two-phase composition of:

• (a) a first phase comprising a biocompatible plastically deformable polymeric matrix having an aqueous fluid sorptivity not greater than 50% by weight, the polymer being insoluble in the environment of use, substantially impermeable to the macromolecule, and containing in admixture therewith;
• (b) a second phase comprising from about 3 to 90 parts by weight of an agglomerated, hydrophilic, aqueous fluid-swellable, aqueous fluid dispersible, biologically active macromolecular material of molecular weight of at least 1000;
• said macromolecular material forming an interpenetrating phase comprising an agglomerate made of a plurality of clusters of macromolecules that form a network of substantially contiguous particles in the polymeric matrix, and
• wherein, when the body is placed in the environment, aqueous fluid will permeate by diffusion into the polymer matrix and be absorbed by the biologically active macromolecular phase, said matrix having channels communicating between the macromolecular particles and the surface of said polymer body, whereby the biologically active macromolecules are continuously released from the matrix over a prolonged period of time.