Characterization of microcrystalline cellulose loaded diclofenac calcium alginate gel beads in vitro.

Diclofenac calcium alginate (DCA) beads containing microcrystalline cellulose (MCC) were prepared using ionotropic gelation method. The effect of MCC amounts on physicochemical characteristics of the DCA beads was examined. The particle size and entrapment efficiency of diclofenac sodium (DS) of the DCA beads increased with increasing amount of MCC. MCC could be involved in the calcium alginate formation to create a complex matrix in the DCA beads, which was revealed using FTIR spectroscopy. The MCC-DCA beads provided greater water uptake in distilled water, but retarded swelling rate in pH 6.8 phosphate buffer. A longer lag time and a similar drug release rate of the MCC-DCA beads in pH 6.8 phosphate buffer were found. The MCC-DCA beads also gave higher drug release rates in distilled water when compared with the DCA beads. However, the increase of MCC content over 0.5% in the DCA beads did not affect the drug release in distilled water. In conclusion, MCC could improve drug entrapment efficiency and modify drug release from the DCA beads.