An anti-inflammatory drug (mefenamic acid) incorporated in biodegradable alginate beads: Development and optimization of the process using factorial design

The objective of this study was to prepare and evaluate biodegradable alginate beads as a controlled-release system for a water-insoluble drug, mefenamic acid (MA), using 3 x 2 2 factorial design by ionotropic gelation method. Therefore, the mefenamic acid dispersion in a solution of alginate was dropped into the cross-linking CaCl2 solution and a fairly high yield (71-89%) of MA-alginate beads were obtained. Their encapsulation efficiencies were in the range of 79.3-98.99%. The effect of drug:polymer ratio, CaCl2 concentration, and curing time on the time for 50% of the drug to be released (t(50%)), and the drug entrapment efficiency were evaluated with factorial design method. It was found that drug:polymer ratio and interaction of drug:polymer ratio and curing time had an important effect on the drug to be released (t(50%)). The effect of CaCl2 concentration is also important on the drug release. On the other hand, all factors except CaCl2 concentration were effective on the drug entrapment efficiency. The swelling properties of beads were also studied. The release mechanism was described and found to be non-Fickian, Case II, and Super Case II transport for the formulations. This study suggested a new mefenamic acid alginate bead formulation for oral delivery of nonsteroidal anti-inflammatory drugs, which cause gastric irritation.