Microfluidic double emulsions and microparticles for the delivery of hydrophilic active pharmaceutical ingredients.

Encapsulation of active pharmaceutical ingredients (API) is widely used in the pharmaceutical industry to control their release over several days or weeks.
Encapsulation of hydrophobic compounds is well controlled by solidifying an O/W simple emulsion. However, entrapping hydrophilic compounds is much more complicated.
We succeeded to solve the problem using a robust three-step process (combining microfluidic technology and standard methods) allowing for production of double emulsion droplets (W/O/W) and then microspheres with controlled properties (morphology, shape, size, peptide content…). Those microspheres have desired properties compatible with control delivery of APIs.
By using two FDA approved polymers, the polycaprolactone (hardly biodegradable) and the poly(lactic-co-glycolic acid) (highly subjected to hydrolysis), we were able to create a simple model describing the release kinetics by either diffusion or erosion. This model seems to be very robust to predict the particle parameters that will release the API at the expected kinetic.
We managed, for the first time, to obtain micro-particles with desired particle size (monodispersed distribution in the range of 5 to 20 µm), whose structure is controlled and adapted to the delivery challenge we address.