Development, physical characterization, micromeritics and in vitro release kinetics of letrozole loaded biodegradable nanoparticles.

The present investigation was aimed at preparing and characterizing biodegradable nanoparticles of letrozole with poly (D,L-lactide-co-glycolide) monomer ratio 50:50. The nanoparticles were prepared by direct precipitation technique. Different formulations were prepared by changing polymer-drug ratio at two different levels of phase volume ratio. The prepared nanoparticles were evaluated for the recovery, drug entrapment efficiency, micromeritic properties and particle size distribution profile, surface morphology and in vitro release kinetics. The results show that the nanoparticles recovery and drug entrapment efficiency vary from 37 to 79% and 12 to 27% respectively. Span value and mean diameter (MD) of different formulations were found to vary from 0.937 to 2.462 and 146 nm to 267 nm, respectively. Field Emission Scanning Electron Microscopy (FESEM) revealed the particles to be spherical with smooth surfaces. Release kinetics fitted the Higuchi model and ensured the capability of sustaining the drug release from the nanoparticles.