UTILIZATION OF SPHERICAL CRYSTALLIZATION TECHNIQUE IN THE PREPARATIONOF SUSTAINED-RELEASE FUROSEMIDE TABLETS

Furosemide microcapsules were prepared by a spherical crystallization technique using acrylic polymers (Eudragit RS 100 and RL 100). The mic rocapsules obtained were spherical with a mean particle diameter of 50 0 and 580 mu m for Eudragit RS and RL respectively. The microcapsules were tabletted, and the physical characteristics of the tablets were r elated to the microcapsule size, core/wall ratio and to the storage at humid atmosphere (40 degrees C, 90% relative humidity). In vitro diss olution studies in phosphate buffer (pH 7.4) showed that the most reta rdant effect was obtained by using larger microcapsules, lower core/wa ll ratio and Eudragit RS. On the other hand, storage did not affect th e amounts of furosemide released from tablets prepared from Eudragit R S microcapsules after 20 to 30 min with a slight decrease in the initi al rate of release. Dissolution data showed that the release followed Higuchi matrix model kinetics.