Bioavailability and ADMET

Bioavailability and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) are fundamental concepts in modern drug discovery and development, serving as crucial determinants of a compound’s pharmacokinetic and pharmacodynamic profiles. Bioavailability defines the fraction of an administered dose of an unchanged drug that reaches the systemic circulation, influencing its therapeutic efficacy. Factors such as solubility, permeability, first-pass metabolism, and molecular properties are key determinants of bioavailability. Lipinski’s Rule of Five and Veber’s Rules provide essential guidelines for predicting drug-likeness and oral bioavailability based on molecular weight, lipophilicity, hydrogen bond interactions, and molecular flexibility. Furthermore, the Bioavailability Score (BAS) is used as a computational metric to estimate the likelihood of a compound achieving sufficient systemic exposure.