Calcium alginate cross-linked polymeric microbeads for oral sustained drug delivery in arthritis.

After the successful optimization and development of a drug entity, design of dosage form then plays an important role. Hence, research continuously keeps on searching for ways to deliver drugs over an extended period of time. With aceclofenac, a novel NSAID used in the treatment of rheumatoid arthritis, frequency of administration may cause certain GI-adverse effects. The objective of the present research work was to develop a microparticulate oral sustained release dosage form, to reduce dosing frequency, to eliminate the dose related adverse effects and to ultimately improve compliance in the pharmacotherapy of arthritis. The microbeads were prepared by an ionotropic external gelation technique, by using sodium alginate as the hydrophilic carrier and calcium chloride as the cross-linking agent. The shape and surface characteristics were determined by scanning electron microscopy (SEM). Particle size distribution was determined by an optical microscope. The physical state of the drug in the formulation was determined by differential scanning calorimetry (DSC). While increasing the concentration of sodium alginate dispersion increased flow properties, mean particle size, swelling ratio and drug entrapment efficiency. The mean particle sizes of drug-loaded microbeads were found to be in the range 596.45 ± 1.04 to 880.10 ± 0.13 μm. The drug entrapment efficiency was obtained in the range of 63.24-98.90% (w/v). The release of drug from the microbeads at pH 1.2 is negligible. Under neutral conditions, the beads will swell and the drug release depends on swelling and the erosion process resulting in an optimum level of drug released in a sustained manner which exhibits zero-order kinetics.