Microenvironment-controlled encapsulation (MiCE) process: effects of PLGA concentration, flow rate, and collection method on microcapsule size and morphology.

Purpose: To evaluate the real-time effects of formulation and instrumental variables on microcapsule formation via natural jet segmentation, a new microencapsulation system termed the microenvironment-controlled encapsulation (MiCE) process was developed.

Methods: A modified flow cytometer nozzle hydrodynamically focuses an inner drug and outer polymer solution emanating from a coaxial needle assembly into a two-layer compound jet. Poly(lactic-co-glycolic acid) (PLGA) dissolved in a water-miscible organic solvent resulted in formation of reservoir-type microcapsules by interfacial phase separation induced at the boundary between the PLGA solution and aqueous sheath.