DETERMINATION OF THE MECHANICAL IMPACT FORCE IN THE IN-VITRO DISSOLUTION TEST AND EVALUATION OF THE CORRELATION BETWEEN IN-VIVO AND IN-VITRO RELEASE

The mechanical impact force in the paddle-beads method was determined. A manometric catheter was passed into the dissolution vessel through a hole, and the mechanical impact force was measured. In the present study, this mechanical force was evaluated as an impulse. The impulse increased with increasing number of beads added in the medium; in particular, the impulse increased markedly with more than 2500 beads in 250 ml dissolution medium. A close relationship was observed between the drug release rate and impulse. The profile of in vitro release using the paddle-beads method with rotation at 25 rpm in 250 ml of medium containing 2500 beads was similar to that of in vivo release in the fasted condition in dogs.