The objectives of this study are to prepare and characterize quercetin nanocrystals by planetary ball milling and to evaluate the influence on the solubility and the dissolution profile. Coarse quercetin was pretreated with ultrasonication prior to wet milling using bead size of 0.1 mm at 800 rpm for 15 and 30 minutes respectively. Particle size analysis showed that the milling process for 15 minutes yielded particles with d50% and d99% of 71.5 nm and 389.9 nm respectively, mean particle size 367.7 nm, the PDI value of 0.338 and the zeta potential 0.17 mV. The increase in milling time to 30 minutes yielded particles with d50% and d99% of 68.3 nm and 352.3 nm respectively, mean particle size 289.9 nm, the PDI of 0.308 and the zeta potential 0.31 mV. There was a significant increase in the solubility of quercetin nanocrystals (P<0.01). Quercetin nanocrystals showed an increase in dissolution profile in 0.1 N hydrochloric acid medium.
