[In vitro studies of drug liberation from suppositories with the rotating flask method]

The official dissolution apparatuses of the U.S.P. XXI or those recommended by the DAC 1979, respectively, are not suitable for the pertinent examination of rectal drug dosage forms. In the literature, on the other hand, numerous experimental setups have been proposed for the study of drug release from suppositories. However, these devices are all rather complicated as concerned with their construction as well as their handling, and, thus, cannot be considered as universally applicable test models. The rotating flask model, that has already been presented to the public earlier, in its two appearances, i.e. the dissolution tester (simple rotating flask) and the absorption model (compartmented rotating flask), can be employed for the testing of drug liberation from suppositories. The release parameters which have been determined in either of the two types of the rotating flask correlate well with each other and are also relevant characteristics of the bioavailability.