A collaborative in vitro dissolution study using the flow-through method

Abstract

A collaborative in vitro dissolution study has been performed in 4 laboratories using the flow-through method at various hydrodynamic conditions. The USP XXI salicylic acid calibrator tablet was used as test formulation. The results obtained by the flow-through method were compared with data generated using the compendial USP XXI paddle method. The flow-through method was found to produce reproducible and corresponding dissolution data both within and among the different laboratories. It can be concluded that the flow-through method does not produce larger variations, expressed in terms of ranges of amount dissolved at various times, compared to the paddle method. In fact, at some flow conditions, smaller variations were obtained with the flow-through method compared to the paddle method. This was confirmed by the coefficients of variation for the time to dissolve 20, 50, and 80% of the salicylic acid. The coefficient of variation was also found to decrease with increasing hydrodynamic intensity for both dissolution methods. The use of deaerated dissolution medium was found to be a critical experimental factor and the need for a proper pretreatment of the medium must be emphasized.