This guidance provides general recommendations regarding the development, evaluation, and use of physiologically based pharmacokinetic (PBPK) analyses for biopharmaceutics applications employed by sponsors of investigational new drug applications, and applicants for new drug applications, or abbreviated new drug applications, and supplements to these applications,  for oral drug product development, manufacturing changes, and controls. PBPK analyses use models and simulations that combine physiology, population, and drug substance and product characteristics to mechanistically describe the pharmacokinetic (PK) and/or pharmacodynamic behaviors of a drug product.