Non-linear Time Scaling for IVIVC: Secrets from an Expert

In vitro-in vivo correlation (IVIVC) is a predictive mathematical tool that describes the relationship between an in vitro property of a drug dosage form and an in vivo pharmacokinetic response. IVIVCs generally employ linear time scaling. Yet sometimes, the IVIVC relationship is better described by a more complex function. For example, some drugs release in vivo at 2 different rates. The release rates for erodible matrices depends on the dosage form’s position in the intestine. For implants, the release rate changes as diffusion is followed by erosion.

If the in vitro test does not account for these possibilities, the in vitro dissolution may exhibit a different shape compared to in vivo release. In this case, a non-linear relationship must be established. Prof. JM Cardot explained how non-parametric approaches can be used to determine time scaling.