Preparation of biodegradable liquid core PLLA microcapsules and hollow PLLA microcapsules using microfluidics.

Biodegradable PLLA capsules with a narrow size distribution were prepared using a microfluidics platform. With this technique, an oil-in-water emulsion was produced in which the polymer, a hydrophobic non-volatile non-solvent and a hydrophobic model drug were dissolved in the organic phase. The polymer precipitated at the droplet interface, yielding a drug deliverable microcapsule of which the release of this model drug was investigated. These capsules with an organic phase in the core were also used to prepare hollow particles by conveniently removing the core phase by lyophilization. Optimal conditions for the preparation of biodegradable capsules were found with respect to the flow rate of the continuous phase and the molecular weight of the PLLA polymer. This approach of preparing biodegradable capsules is of potential interest for the field of drug delivery.