Ketoprofen lysine because of a short half-life (1-2 h) multiple dosing regimens are required for oral administration. For this reason, this study is concerned with the preparation of poly lactic-co-glycolic acid-based spray-dried nanoparticles to extend the activity of the ketoprofen lysine. Nanoparticles were produced with a spray dryer (B-90, Buchi, Switzerland) and solid state properties of nanoparticles were analysed using scanning electron microscopy, particle size, polydispersity index, zeta potential, nuclear magnetic resonance spectroscopy, X-ray and differential scanning calorimetry. Drug release from nanoparticles was studied using the dialysis bag method in simulated gastrointestinal environment (pH 7.4). Ketoprofen lysine-loaded particles demonstrated nanostructured and spherical shape while in vitro release studies showed extended release (similar to 8 days) of ketoprofen lysine incorporated and also a fairly good entrapment efficiency (similar to 59-78 %) was detected. Peppas-Sahlin kinetic model was found to fit the best using DD Solver software program. This research may be useful for long-term and optimum use of oral non-steroidal antiinflammatory drug in chronic inflammatory diseases.