Dissolution Devices for Simulation of in vivo Conditions

Abstract

Drug release from solid oral dosage form is affected by biochemical and mechanical factors in the upper gastrointestinal tract (GIT). The dosage form is exposed to different conditions in GIT sections and to food effects. Precise simulation of in vivo environment is essential for achieving biorelevant conditions by the in vitro method. New dissolution devices are developed for this purpose. The static devices are mainly used for evaluation of mechanic and hydrodynamic forces (the paddle-beads and rotating beaker method). Nevertheless, the complex dynamic dissolution device represents the required aim. Simple dynamic equipment modifies attributes of the established USP 2 apparatus (the artificial stomach-duodenum model). The dynamic equipments with a new design simulate the whole upper GIT (TIM-1) or itself stomach (the dynamic gastric model and the human gastric simulator). Adequate simulation of in vivo conditions by in vitro tests ensures better prediction of the drug behavior and facilitates the development of new dosage forms.