High celecoxib-loaded nanoparticles prepared by a vibrating nozzle device

Drug delivery research has resulted in the availability of several enabling technologies for formulating poorly water-soluble compounds. In this study the vibrating nozzle device, originally used for encapsulation of drugs, cells and microorganisms, has been used to formulate nanoparticles (NP) with high loading capacity. Celecoxib was incorporated in NP of polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) and the influence of polymers, initial drug : polymer ratio and stabilizer concentration on NP size and surface properties, entrapment efficiency, drug loading and in vitro release profile were investigated. NP were in the size range of 230-270 nm, with a polydispersity index less than 0.25 and a spherical shape. The highest celecoxib loading (13% w/w) was obtained at initial ratio celecoxib : Resomer RG 502 (PLA/PGA 50/50) of 1:5 and 0.1% w/w polyvinyl alcohol concentration. Thermal analysis and X-ray diffraction suggested that celecoxib was amorphous or molecularly dispersed in the polymeric matrix. The release profile exhibited an initial burst followed by sustained release. The freeze-dried NP could be completely dispersed on addition of lyoprotectants. The production of NP by the vibrating nozzle device is highly reproducible, time saving, can be performed under aseptic conditions and offers the possibility of scale-up.