diclofenac sodium-loaded eudragit® microspheres: optimization using statistical experimental design

in this study, polymeric microspheres containing diclofenac sodium were prepared by single emulsion (oil-in-water) solvent evaporation method and evaluated for their size, morphology, encapsulation efficiency, drug loading, and in vitro drug release.

methods

two nonbiodegradable polymers, eudragit® rs100 and rl100 were used in combination. microspheres were prepared by varying the amount of polyvinyl alcohol as a surfactant (0.05, 0.125, and 2.0 %, w/v) to the external phase; varying the amount of polymer (1:1, 2:1, and 3:1, w/w) to the drug by employing 32 full factorial design using the design expert (version 8.0.7.1). the drug polymer interactions were investigated by fourier transform infrared spectroscopy (ftir) and x-ray powder diffractometry (xrpd). imaging of particles was performed by field emission scanning electron microscopy.

results

graphical and mathematical analysis of the design showed a quadratic model was significant for the responses. low magnitude of error and significant values of r 2 proves the high prognostic ability of the rsm. encapsulation efficiency of microspheres (41.13 to 65.33 %) increases with an increase in surfactant concentration but decreases with an increase in polymer concentration. the microspheres were found to be discrete, spherical with smooth surface. the absence of drug polymer interactions was confirmed by ftir spectroscopy. xrpd revealed the dispersion of drug within microspheres formulation. the perfect ph-independent release profile was achieved from eudragit® microspheres by anomalous transport mechanism.

conclusions

in conclusion, eudragit® microspheres containing diclofenac sodium can be successfully prepared, and seem to be promising for sustained release application.