Implant devices for modulating bioactive agent release profiles

An implant device comprising an inner core having a longitudinal surface surrounded by a membrane sheath and having exposed proximal and distal end surfaces that are not surrounded by the membrane sheath;

• wherein the inner core comprises a biodegradable polymer having a bioactive agent dissolved or dispersed therein;
• wherein the membrane sheath comprises a biocompatible polymer and is substantially free of the bioactive agent;
• and
• wherein at least one of the exposed proximal or distal end surfaces has a surface morphology formed by a fluid-treatment of the exposed proximal or distal end surface.

An implant device prepared by a process comprising:

• a. extruding an admixture of a biodegradable polymer and a bioactive agent through an inner coaxial nozzle to form a core;
• b. forming a composite strand by simultaneously coextruding a biocompatible polymer through an outer coaxial nozzle to apply a substantially coextensive membrane sheath surrounding the core;
• c. cutting the composite strand of step (b) into one or more slats comprising a longitudinal surface and two end surfaces;
• and
• d. contacting at least one end surface of the one or more slats from step (c) with a sufficient amount of a fluid for a sufficient time to change the surface morphology of the at least one end surface to thereby provide the implant device.