Bioequivalency evaluation by comparison of in vitro dissolution and in vivo absorption using reference equations.

Using in vitro dissolution and in vivo absorption of different generics or batches for an appropriate drug and dosage form, a reference equation of form: ka = a+bkd+dkd2 can be proposed. In the case of availability of standardised in vitro-in vivo data for a specific drug, a Level A a correlation of this type containing experimentally determined a, b, d parameters would serve to predict in vivo absorption phase of the drug. The larger number of batches, the stronger will be the predictive power of these parameters.