Factorial design formulation optimization and in vitro characterization of curcumin-loaded PLGA nanoparticles for colon delivery

We have employed a 23 factorial design approach for optimizing curcumin-loaded PLGA nanoparticles with a specific interest in colon treatment. Curcumin-loaded PLGA nanoparticles were prepared by using the single emulsion solvent evaporation technique. In vitro characterizations of the curcumin-loaded nanoparticles revealed that the mean particle sizes of the nanoparticles ranged from 181.5 nm to 206.9 nm, the zeta potential values were in the range of -30.6 to -41.7 mV, the encapsulation efficiencies were between 58.1 and 83.2% and the drug release from the formulations was in the range of 34.4-62.8%. The properties of the optimized curcumin-loaded PLGA nanoparticles predicted by the 23 factorial design approach correlated very well with the experimentally determined particle size of 219.6 nm, zeta potential of 36.8 mV, encapsulation efficiency of 74.4% and a 56.2% cumulative drug release after 24 h. In vitro cellular uptake studies with HT-29 cells showed that the optimized curcumin-loaded PLGA nanoparticle exhibited a much higher cellular uptake of curcumin (i.e. 7.01 +/- 0.33 mu g/10(6) cells) than a native curcumin solution (3.74 +/- 0.56 mu g/10(6) cells). Stability studies also showed that all investigated formulations were stable at least for 2 months. (C) 2016 Elsevier B.V. All rights reserved.