Influence on variation in process parameters for the design of xanthan-gum-facilitated ethyl cellulose microparticles for intestinal specific delivery

Abstract Xanthan-gum-facilitated aspirin-loaded ethyl cellulose microparticles were prepared by multiple-emulsion solvent evaporation technology and the impact on variation in process parameters was investigated systematically. Scanning electron microscopy was performed to determine the surface morphology of the microparticles before and after dissolution study. X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) analysis were performed, and yield value, swelling study, encapsulation efficiency, flow properties and dissolution profiles of the prepared formulations were evaluated. The size of microparticles varied between 247 and 410 μm, and 58.34% drug entrapment efficiency was achieved depending on the variation in process parameters. The drug release in acid solutions was slower than in alkaline solution. The microparticles provided extended drug release in alkaline dissolution medium, and the drug release was found to be controlled by Fickian diffusion mechanism. XRD and DSC analyses revealed the amorphous nature of drug in the microparticles. FTIR data indicated the stable character of the encapsulated drug in the microparticles. Thus, variation in process parameters showed a slow and prolonged release of aspirin in simulated intestinal fluid.