title: Preparation and characterization of amorphous ezetimibe nanosuspensions intended for enhancement of oral bioavailability.
abstract: OBJECTIVE
  The objective of this study was to prepare and investigate better and stable amorphous ezetimibe nanosuspensions for oral bioavailability enhancement.
  
  
  METHODS
  Nanosuspensions of ezetimibe were prepared by solvent-antisolvent precipitation technique using the surfactant, Tween 80 as stabilizer. The nanosuspension preparation was optimized for particle size by investigating two factors that is, solvent:antisolvent ratio and surfactant concentration, at three levels. The formulations were characterized for particle size, surface morphology, crystallinity, zeta potential, saturation solubility, in vitro drug release and in vivo drug absorption.
  
  
  RESULTS
  The nanosuspensions of ezetimibe were successfully prepared using solvent-antisolvent precipitation. The two factors solvent:antisolvent ratio and surfactant concentration influenced the particle size of the nanosuspensions prepared. Nanosuspensions were smooth and spherical. The X-ray powdered diffraction and differential scanning calorimetry results indicated that the antisolvent-solvent method led to the amorphization of ezetimibe. Under storage, the amorphous ezetimibe nanosuspensions demonstrated significant physical stability. Ezetimibe nanosuspensions increased the saturation solubility to an extent of 4-times. Ezetimibe nanosuspensions completely dissolved in the dissolution medium within 1 h, while pure drug was dissolved up to 42% during same time. The Cmax with ezetimibe nanosuspension was approximately 3-fold higher when compared with that of ezetimibe conventional suspensions administered orally.
  
  
  CONCLUSIONS
  Stable amorphous ezetimibe nanosuspensions were successfully prepared and these nanosuspensions demonstrated dramatic improvement in oral bioavailability of the active.
authors.affiliation: Department of Pharmaceutics, Mother Teresa College of Pharmacy, Osmania University, Ghatkesar, India.
authors.forename: Kiran
authors.initials: K
authors.lastname: Thadkala
authors.affiliation: Department of Pharmaceutics, Mother Teresa College of Pharmacy, Osmania University, Ghatkesar, India.
authors.forename: Prema Kumari
authors.initials: PK
authors.lastname: Nanam
authors.affiliation: Department of Pharmacology, Geethanjali College of Pharmacy, Keesara Gutta, India.
authors.forename: Bathini
authors.initials: B
authors.lastname: Rambabu
authors.affiliation: Department of Chemical Engineering, University College of Technology, Osmania University, Hyderabad, Andhra Pradesh, India.
authors.forename: Chinta
authors.initials: C
authors.lastname: Sailu
authors.affiliation: Department of Pharmaceutics, Mother Teresa College of Pharmacy, Osmania University, Ghatkesar, India.
authors.forename: Jithan
authors.initials: J
authors.lastname: Aukunuru
keywords: Dissolution rate; ezetimibe; nanosuspension; oral bioavailability; solvent-antisolvent precipitation