Pharmaceutical powder production by spray-freeze-drying technique : design and optimization of experimental parameters.

Abstract

Spray-freeze-drying (SFD) has emerged in the last decade as a manufacturing technique for proteins and other heat-sensitive compounds. However, its application to nano-medicines has not been explored. Hence, the purpose of this project is to develop and optimize the SFD conditions for the production of nano-aggregates.

In the preliminary SFD experiments conducted using silica nanoparticles (NPs), experimental parameters such as the concentration of the feed, type of exicipients used, feed and air flow rates were varied systematically to observe their influence on the particle characteristics. The findings from this study agreed well with previous SFD experiments that used protein solutions. Following that, a variety of excipients were tested to be included in the nanoparticulate feed suspension. The results of mannitol as an excipient for the SFD nano-aggregates are promising, as the particles exhibit improvements in aerosolization properties. PVA displayed potential in its unique particle morphology, which may have benefits in the re-dispersibility of the nano-aggregates in aqueous media.

With the advantages of SFD and nanoparticulate technology, further tests can be carried out to optimize the aerosolization efficiency and re-dispersibility of the nano-aggregates for effective pulmonary drug delivery.