Method Profile

PBPK-Informed Machine Learning for Gastric-pH Drug Interactions

Train an exposure-ratio predictor on virtual weak bases generated with PBPK simulations, then compare predictions with separate clinical interaction observations.

Intestinal SafetyComputational Models
Three stages connect 14 reference PBPK drugs, 4,339 virtual training compounds and eight external clinical drugs; alpelisib’s observed AUC ratio of 0.70 is compared with a prediction of 0.95.
PBPK-generated training and a separate clinical test answer different questions; alpelisib illustrates a missed interaction category. (NAMs Insights)

Research Applications

Prioritize fasting, immediate-release compounds for detailed acid-reducing-agent interaction assessment.

Model & Design

GastroPlus 9.8.2 physiological absorption/disposition models for 14 reference weak bases; 4,339 retained virtual compounds; eight additional clinical drug comparisons.

Experimental Format

Simulated baseline gastric pH 1.3 versus elevated-pH conditions; XGBoost decision-tree boosting predicts the interaction ratio of area under the concentration–time curve (AUC); 80:20 development/test split and fivefold tuning.

Model Components

  • Component

    Reference and simulated data

    Description

    Literature-derived drug parameters and observed PK/interaction studies; 5,000 generated virtual compounds reduced to 4,339 after excluding AUC ratios below 0.10.

  • Component

    Independent clinical comparison

    Description

    Observed AUC interaction ratios for eight further drugs; separate mechanistic PBPK estimates retained as a comparator.

Measurements & Endpoints

  • Interaction AUC ratio
  • Numerical prediction error
  • Interaction category at the 0.80–1.25 interval
  • Feature-attribution patterns

Analysis

Distinguish agreement with PBPK-generated labels from agreement with clinical observations. Evaluate continuous ratios and binary interaction categories separately.

Published Evidence

  • Study Design

    Develop on simulated compounds, then compare eight further drug-level clinical observations with XGBoost and PBPK estimates.

    Study Sample

    14 reference drugs and 18 reference interaction studies; 4,339 virtual compounds; eight external drugs.

    Comparison

    Simulated labels for internal testing; observed clinical ratios and separately calculated PBPK predictions externally.

    Finding

    Simulated test R² 0.98 and mean absolute percentage error 2.64%. All eight clinical predictions were within twofold; seven of eight interaction categories were correct. Alpelisib was observed at 0.70 but predicted at 0.95.

    Interpretation & Limits
    • Virtual properties lack real-world correlation structures.
    • PBPK simulation bias can propagate into machine learning.
    • Clinical external comparison has only eight drugs.
    • Scope excludes fed conditions, modified-release formulations, Cmax and Tmax.

Sources

  1. Machine Learning Enables Rapid Prediction of Acid‐Reducing Agent Drug Interactions: A Streamlined Complement to PBPK Modeling. CPT: Pharmacometrics & Systems Pharmacology. 2026-07-31. DOI: 10.1002/psp4.70314. ↗