In Vitro-In Vivo Correlation (IVIVC): Prediction of pK a at 37°C, From the Measured Value at 25°C

Purpose.  Most of the drug pKa values have been determined at 25°C, instead of physiologically-relevant 37°C.  The aim of this study is to develop a simple model to predict drug pKa values at 37oC from their corresponding 25oC values.  This is expected to improve the in vitro-in vivo correlation (IVIVC) in some cases, and get an improved understanding of the drug absorption process.

Conclusion.  The model we developed is simple to apply to investigative dissolution rate studies done at 37oC, to mechanistic cellular studies, such as Caco-2, as well as to other physiological condition-based measurements.