A perspective on the current use of the phase distribution model for predicting milk‐to‐plasma drug concentration ratio

Abstract

The phase distribution model, proposed by Atkinson and Begg in 1990, has been widely used for predicting breastmilk‐to‐plasma drug concentration ratio. However, misrepresentations of the equations have been noted in recent publications. In this perspective, we revisit the derivation of the equations and provide an R/Shiny interface for the model with a view to helping scientists in this field acquire in‐depth understanding of the theoretical background and implementation of the model.

Assessment of Infant Exposure to Antidepressants through Breastfeeding: A Literature Review of Currently Available Approaches

“…Weak-based drugs are therefore more likely to diffuse into, and then be trapped in, milk. The unbound distribution model, also named the pH partition model, based on the pH partition theory, uses a rearranged form of the Henderson-Hasselbalch equation to predict the unbound M/P ratio (Mu/Pu) [22]. Atkinson and Begg further improved the pH partition model and developed a phase distribution model with a similar principle to that proposed by Fleishaker et al [23][24][25].…”