Preparation of Diclofenac Sodium Composite Microparticles with Improved Initial Release Property


Department of Materials Engineering,Tabriz University


The aim of this study is the evaluation of the effect of microencapsulation of nanoparticles
in composite microparticles on the reduction of burst release. Microparticles (simple and composite)
and nanoparticles were prepared by using water-in-oil-in-water (W/O1/W2 double-emulsion solvent
diffusion/evaporation method), using different drug/polymer ratios. For preparation of the composite
microparticle, nanoparticle suspension was used as the internal phase. In this investigation, the
microparicle, nanoparticle and composite microparticle formulations prepared were characterized by
loading efficiency, yield, particle size, zeta potential, XRD (X-ray Diffractometry), FTIR (Fourier
Transform Infrared Spectroscopy), DSC (Differential Scanning Calormetry) and drug release. The best
drug of the polymer ratio in the microparticle and nanoparticle were F3 (0.4:1) and NP1 (0.1:1), which
showed 26.89% and 9.07% of entrapment, loading efficiency 94.2 %, 99.44% and mean particle size
13.114 m and 756 nm, respectively. The drug loading microparticle, COM3 (nanosuspension with 0.2.:1
drug/polymer ratio), showed 28.56% of entrapment, loading efficiency 99.96% and mean particle size
13.013 m. The burst was significantly lower with composite microparticles and may be explained by
the slower di usion of the drugs through the double polymeric wall formed by the nanoparticle matrix,
followed by another di usion step through the microparticle polymeric wall.