Early development drug formulation on a chip: Fabrication of nanoparticles using a microfluidic spray dryer
microfluidics, drug delivery, spray drying
The authors have created a microfluidic device for the efficient formulation of drug substances. The device combines one or two different solvents to create a nanosuspension of a drug and sprays small droplets of this suspension onto a substrate, where the droplets dry and the drug assembles in amorphous aggregates.
Compared to previous devices that have been designed for the same purpose this one has several advantages. First of all, it is capable of creating much smaller droplets (with diameter ~60-80nm, compared to ~1μm), which leads to the final production of drug aggregates with much larger surface area. Since the chemical activity of drugs increases with their surface area (because more of the active substance is brought in contact with the environment it is supposed to interact with) this is important, not only because it can lead to more efficient drugs but also because it allows more extensive experimentation with new substances at the initial stages of their development, when they are only produced in small quantities. The bioavailability of the drugs can be further enhanced in this device by the fact that they can be composed of amorphous aggregates instead of crystalline ones if one of the solvents used is a crystallization ihnibitor (PVP - poly(vinyl-pyrrolidone)).