Clinical pharmacokinetic data of racemic drugs obtained by the indirect method following precolumn diastereomer formation: is the influence of racemization during chiral derivatization significant?

This report reviews the stereoselective data of a number of racemic drugs (n = 17) obtained from indirect chiral method (via diastereomer formation) in comparison to similar data generated by the application of a direct chiral method. While it was noted that the indirect method still continued to be used to characterize the stereoselective disposition of racemic drugs, the present review critically evaluates the issue of racemization that has the potential to skew the stereoselective data obtained from the indirect method. The review describes various remedies to counter and/or minimize the impact of racemization on the final outcome of the stereoselective analysis by the indirect method. On the basis of this review it could be concluded that the indirect method is a viable and important tool for gathering stereoselective data of racemic drugs used in medical practice as well for those racemic drugs still in discovery and developmental stages.