The amounts of loading level for beads were given in Table 1.
In vitro release of the diclofenac sodium from magnetic beads was evaluated by immersing of certain amount of drug loaded mag- netic beads into 20 mL buffered solutions with pH 1.2 and 7.4. The releasing studies were carried out on a shaker (90 rpm and) at ambi- ent temperature. At specific time intervals, 5 mL of aliquots of the solution was withdrawn and this volume of aliquots was replaced by 5 mL of fresh buffered solution. The amount of released drug was determined spectrophotometrically at max = 276 nm. The cumula- tive release (R, %) of drug from beads was calculated according to the following equation: