This invention provide novel compositions, methods and devices for sustained drug delivery. The compositions can include a fluid carrier； a plurality of first polymeric microparticles having a bioactive agent dispersed in the fluid carrier； and a plurality of second polymeric microparticles having a visualization agent dispersed in the fluid carrier with the first microparticles. Alternative compositions can include: a fluid carrier； and a plurality of polymeric microparticles having a bioactive agent encapsulated therein and a visualization agent on a surface of the polymeric microparticles, the plurality of polymeric microparticles being dispersed in the fluid carrier. The microencapsulated sustained drug delivery compositions are deposited using oscillating needle apparatus oscillating at 10-12000 minutes per minutes at an amount of 1.0E-03 mL to 1.0E-16 mL per injection.
