ABSTRACT
This study establishes and optimizes the physiologically based pharmacokinetics (PBPK) model for dapagliflozin, predicts the drug distribution into relevant tissues, and calculates the inhibitory effect on the sodium-glucose cotransporters (SGLTs) in the intestine and renal proximal tubule. Based on literature data, a PBPK model for oral administration in healthy adults was established and the predicted blood concentration-time curve characteristics, the main pharmacokinetic parameters (PK), and drug excretion in urine were compared with the published data. To verify and optimize the model and verify the accuracy of the tissue distribution and concentration predictions, a pharmacodynamics model (PD) was established. Urine glucose excretion (UGE) was simulated at the corresponding times. The characteristics of the drug-time curve predicted by the model are similar to those of the measured curve, and the ratio of the main PK parameters to the measured values is within a two-fold range; the accuracy of the established PBPK model is good. The maximal inhibition obtained with 10 mg of dapagliflozin on the duodenum and jejunum segment sodium-glucose co-transporter 1 (SGLT1s) was 1.6%-4.7%, and the inhibition rate of the sodium-glucose co-transporter 2 (SGLT2s) in the proximal tubule of the kidney was as high as 99.9%. At a dose of 10 mg, dapagliflozin delayed intestinal glucose absorption while occupying most of the sites (99.9%) of the renal sodium-glucose cotransporter 2 and inhibiting its glucose reabsorption. This physiological-pharmacokinetic model for dapagliflozin in healthy adults can provide meaningful guidance for exploring pharmacological mechanisms and potential toxicity of gliflozin by simulating drug distribution in different tissues.