Freeze Drying: Potential for Powdered Nanoparticulate Product

Abstract

Nanoparticles were prepared by using an emulsion solvent evaporation method. Further, the drying of an anti-cancer drug of proprietary nature (nanosized) was carried out by a freeze-drying technique to get a free-flowing powder. A systematic approach was developed to study the freeze-drying technique for polymeric nanoparticles. Initially, the freeze-thawing experiments were carried out with varying concentrations of cryoprotectants to screen the most suitable cryoprotectant. Subsequently, the freeze drying was carried out with the selected cryoprotectants to study their effect on the final product quality after drying. Annealing experiments were carried out to optimize the freeze-drying cycle time and study its effect on the particle size of nanoparticles. The effect of selected cryoprotectant on the heat and mass transfer parameters was also studied. Finally, the simulation of the freezing temperature was carried out by using MATLAB 7.0 software. The lyophilized product was characterized in terms of appearance and particle size by photon correlation spectroscopy (PCS) and X-ray powder diffraction (XRD). The lyophilized product obtained with mannitol (0.2% w/v) and lactose (0.5% w/v) as cryoprotectant resulted into a slight increase in particle size after freeze drying.