Solidification of nanostructured lipid carriers (NLCs) onto pellets by fluid-bed coating: Preparation, in vitro characterization and bioavailability in dogs

There are demands to solidify nanoparticle suspensions to overcome problems associated with liquid formulations. In the present study, the liquid nanostructured lipid carriers (NLCs), which were comprised of Precirol ATO 5, Captex100, Tween-80 and fenofibrate as the model drug, was prepared by the melting-emulsification method and converted to solidified NLC pellets by fluid-bed coating technique. To achieve good coating, polyvinylpyrrolidone K17 was used as the coating polymer to entrap the NLCs. Physical characterization indicated good appearance and confirmed nonexistence of crystalline fenofibrate in the solidified NLC pellets. More than 90% NLCs could be released from the solidified NLC pellets within 15 min. The reconstituted NLCs had spherical morphology similar to the original NLCs, but had an average particle size of 227.5 nm which was significantly larger than 94.1 nm of the original ones. However, both solidified NLC pellets and original NLC suspension showed similar in vitro lipolysis profiles and similar pharmacokinetics parameters in beagle dogs. Results indicated that fluid-bed coating could be a useful tool for the solidification of NLC suspension.