Producing dry insulin nanoparticles through spray drying may open the door to dosage forms such as oral tablets or bioadhesive films, according to research published in the Nature journal Scientific Reports.
In the paper, researchers at The University of British Columbia describe work to assess how spray drying and freeze-drying affect the structures of insulin-loaded nanoparticles, both with and without mannitol as cryoprotectants. The team performed the research to determine the best way to create stable insulin nanoparticles that are loaded with enough active ingredients to achieve its therapeutic window.
While the researchers see freeze-drying technology as the current gold standard for creating stable insulin nanoparticles, they identified low loading content as a limitation that hinders oral delivery. The low insulin loading content stems from the fact cryoprotectants occupy most of the nanoparticles.
In light of the limitation, the team identified spray drying as a way to potentially produce nanoparticles that are stable and, because the process renders cryoprotectants unnecessary, have high insulin loading content. The study generated evidence to support the hypothesis.
“Insulin [nanoparticles] spray dried without mannitol showed the smallest mean particle sizes and highest loading content when redissolved. These results suggested that the dry insulin [nanoparticles] produced by spray drying with no mannitol were most suitable for further processing into other anhydrous dosage forms such as oral tablets or bioadhesive films,” the authors wrote.
The researchers evaluated the reconstitution capacity of the nanoparticles by measuring their size distribution, surface charge, encapsulation efficiency and loading content. Other assessments looked at the quality of the redissolved nanoparticles through assessments of insulin protection effects, release behaviors and cellular uptake efficacy.