Inside Dolomite Labs: PLGA Multiple Emulsions for Hydrophilic Drug Delivery

Poly(lactic-co-glycolic acid) or PLGA is a biocompatible polymer that has broad utility and is widely employed for drug encapsulation and controlled release of the drug over time. PLGA particles can also be coated, for example with an antibody, to target specific sites for drug release.

Since many active pharmaceutical ingredients (APIs) are designed to be soluble in aqueous media, it can be advantageous to dissolve the API in an aqueous solution and form an initial water-in-PLGA emulsion. This is then fed through a standard 100 µm Dolomite chip to create a water/PLGA/water multiple emulsion. The Dolomite Team is using microfluidics to produce PLGA multiple emulsions. PLGA multiple emulsions are obtained using a two-steps microfluidic method: water/PLGA in dichloromethane (DCM) droplets are produced in a first 14 µm standard droplet hydrophobic chip (Figure 1) and then introduced into a second 100 µm 3D pore junction hydrophilic chip (Figure 2) to form the final multiple emulsion. DCM is finally evaporated, and different sizes of dry beads (30-80 µm) containing small aqueous inner droplets (1-20 µm) are produced depending on the flow rates adopted respectively.

Figure 1. Water/PLGA in DCM droplets produced in the first 14 µm standard droplet hydrophobic chip. 

Figure 2. Water/PLGA in DCM/Water multiple emulsion produced in the second 100 µm 3D pore junction hydrophilic chip

Figure 3. Final Water/PLGA in DCM/Water collected multiple emulsion

As a result of this experiment,  Dolomite Team has developed specific protocols and surfactants for the production of PLGA multiple emulsion of different sizes.

If you are interested in producing PLGA multiple emulsion beads for your applications, please contact us at info@dolomitemicrofluidics.com, and keep an eye out for our application note showing the production method, which we will be releasing onto the website in the near future.