Abstract
Some of the factors that cause interindividual and intraindividual differences in drug absorption from orally administered formulations are derived from the differences in pharmaceutical properties of the drugs and their formulations by the fluctuations of gastrointestinal physiology and their differences among patient populations. Especially gastrointestinal pH and gastric emptying rate significantly impact variability of drug absorption, and the difference in bile secretion in fed or fasted state further complicates it. Formulation evaluation technologies that precisely reflect fluctuations in gastrointestinal physiology such as individual patient’s age, illness, co-administered drugs, and fed or fasted, can support formulation development with small fluctuations in drug absorption. Furthermore, it is expected to become an evaluation technology that supports the era in which formulations are designed and manufactured individually for each patient.
