Development of an oral rutin nanocrystal formulation

Dried rutin nanocrystals have been prepared by lyophilization and investigated regarding their physicochemical properties with respect to re-dispersability, particle size, morphology and dissolution behavior. Photon correlation spectroscopy (PCS) and laser diffractometry (LD) were employed to determine the particle size. Morphology of the particles was analyzed by light microscopy. Lyophilized rutin nanocrystals were incorporated into tablets and the dissolution behavior of the tablets was evaluated. Very fine particles of lyophilized rutin could be completely re-dispersed in the water. The PCS size average and polydispersity index (PI) of lyophilized rutin were of 721 nm and of 0.288 after re-dispersion. The rutin nanocrystal-loaded tablets were produced using direct compression. The dissolution velocity of the rutin nanocrystal-loaded tablet was superior compared to rutin microcrystal-loaded and a marketed tablet. After 30 min rutin was released and dissolved completely from the nanocrystal tablets in water. In contrast, only 71% and 55% of the total amount of rutin were dissolved from the microcrystal tablets and the marketed tablet, respectively. The improving dissolution behavior of the rutin nanocrystal-loaded tablet should lead to a better bioavailability of the poorly soluble rutin in the body.