PREPARATION AND CHARACTERIZATION OF A NEW CONTROLLED RELEASE IBUPROFEN SUSPENSION FOR IMPROVING SUSPENDABILITY

A new controlled release suspension of ibuprofen was developed by using ibuprofen microspheres with an acrylic polymer (Eudragit RS-PM(TM)). Uniform dispersibility of the microspheres for a period of more than 6 months could be obtained in a low viscous acidic solution of sodium carboxymethylcellulose (CMC) by the addition of D-sorbitol. The presence of D-sorbitol in the acidic medium increased the adsorbed amount of CMC on the microspheres and contributed to build the loose three-dimensional networks of CMC. The coarse microspheres covered with CMC were considered to be held in the networks. This structure of CMC made it possible to maintain the long-term uniform dispersibility. An in vitro drug release test showed no influence of the adsorbed CMC on the release rate. Leakage of drug from the microspheres in the suspension was not found to occur on storage for 6 months.