Evaluation of disintegrating time of rapidly disintegrating tablets by a paddle method.

A paddle method for measurement of the disintegrating time of orally disintegrating tablets with rizatriptan benzoate as a model drug was evaluated. The paddle method employed a dissolution test assembly with tablets immersed in disintegrating medium through a fastened sinker. Paddle stirring rate, opening of the sinker sieve, and tablet crushing strength influenced disintegrating time greatly. A logarithmic relationship was observed between disintegrating time and paddle revolution speed, while disintegrating time values and tablet crushing strength were fitted to a linear equation. The paddle method values with limited deviation were in good correlation with in vivo results. The paddle method was employed to optimize the disintegrating time of rizatriptan benzoate orally disintegrating tablets using a factorial design. The best-fit quadratic equation with a regression coefficient of 0.996 was highly predictive, which was indicative that the paddle method was precise and applicable in formulation optimization.