Comparison of Homogenization and Precipitation Techniques for Production of Quercetin Nanocrystals

The aim of this study was to compare the production of nanocrystals of a poorly watersoluble antioxidant, quercetin, by top-down and bottom-up techniques. The top-down method used was high pressure homogenization (HPH) and bottom-up method of evaporative precipitation of nanosuspension (EPN) was used and the products from both these methods were compared. The particle size of the original drug was about 34 μm. The smallest average particle size obtained from HPH was 483 nm and after lyophilisation it was 575 nm, and from EPN it was 739 nm. The dissolution rate of the quercetin nanocrystals prepared by both the methods enhanced manifolds compared to the original quercetin. The antioxidant activities of the quercetin nanocrystals were better than the original drug. Our study demonstrated that both the methods can successfully prepare quercetin nanocrystals. HPH produced smaller crystals, which presented slightly better dissolution than those produced by the EPN. However, EPN is a simple process compared to the energy intensive HPH and is cost effective.