Influence of formulation and process parameters on the formation of coated solid dispersion nano- and microparticles by single step coaxial electrospraying

The number of new drugs with low aqueous solubility and hence low therapeutic efficiency is very high. One formulation strategy to increase the solubility and the uptake in the body is the use of amorphous solid dispersions (this is a solid product that is made up of a non-crystalline polymer in which the drug is chaotically distributed but that releases the drug upon contact with water). Often such an instantaneous release needs to be delayed to avoid fast precipitation of the poorly soluble drug in the gastrointestinal tract, in case of formulation of powders for reconstitution or when one wants to target the drug to specific sites in the gastrointestinal tract. Delayed release can be achieved by bringing the dispersions into the form of coated tablets, but those are difficult to administer to very young or elderly patients. Much better would be a delayed release from the single dispersion particles (that could be given in a liquid suspension to a wide variety of patients). We recently found that co-axial electrospraying has the potential to prepare coated solid dispersion submicron particles in one single step. However, the observed variability in coating efficiency points to the lack of fundamental understanding of the process. Hence the general objective of this project is to identify and quantify the process and formulation parameters as well as their interplay in order to design future processes based on scientific rationale instead of trial-and-error.