The " dissolution" method: a low volume, in vitro apparatus for assessing the dissolution/precipitation behaviour of an active pharmaceutical ingredient under biorelevant conditions.

This paper describes a low volume, in vitro apparatus for investigating the dissolution and precipitation behaviour of active pharmaceutical ingredients (APIs) under a wide range of experimental conditions and dissolution media. The apparatus has automated and dynamic pH control, allowing the simulated passage of drugs through the gastrointestinal tract (GIT). Experiments can be performed in the presence of biorelevant media and excipients, providing information related to the predicted behaviour of APIs under physiological conditions. The technique is described in detail and results are presented for a number of neutral, basic, acidic and ampholytic drug compounds.