Introduction: The objectives were to prepare, characterize and in vivo evaluate different ibuprofen (IBU) nanosuspensions prepared by ultra-homogenization, after oral administration to rabbits. Methods: The nanosuspensions produced by ultra-homogenization were tested and compared with a marketed IBU suspension for particle size, in vitro dissolution and in vivo absorption. Five groups of rabbits received orally 25 mg/kg of IBU nanosuspension, nanoparticles, unhomogenized suspension, marketed product and untreated suspension. A sixth group received 5 mg/kg IBU intravenously. Serial blood samples were obtained after IBU administration. Results: The formulated nanosuspensions showed significant decrease in particle size. Polyvinyl Pyrrolidone K30 (PP) was found to improve IBU aqueous solubility much better than the other tested polymers. Addition of Tween 80 (TW), in equal amount as PP (IBU: PP:TW, 1:2:2 w/w) resulted in much smaller particle size and better dissolution rate. The Cmax achieved were 14.8±1.64, 11.1±1.37, 9.01±0.761, 7.03±1.38 and 3.23±1.03 μg/ml and the tmax were 36±8.2, 39±8.2, 100±17.3, 112±15 and 105±17 min for the nanosuspension, nanoparticle, unhomogenized suspension, marketed IBU suspension and untreated IBU suspension in water, respectively. Bioavailability of the different formulations relative to the marketed suspension were the highest for nanosuspension> unhomogenized suspension> nanoparticles> untreated IBU suspension. Conclusion: IBU/PP/TW nanosuspensions showed enhanced in vitro dissolution as well as faster rate and higher extent of absorption as indicated from the higher Cmax, shorter tmax and larger AUC. The in vivo data supported the in vitro results. Nanosuspensions prepared by ultra-high-pressure-homogenization technique can be used as a good formulation strategy to enhance the rate and extent of absorption of poorly soluble drugs.
In vitro and in vivo Evaluation of Ibuprofen Nanosuspensions for Enhanced Oral Bioavailability
