Dissolution tests of pharmaceutical tablets using a novel gastric simulator

A new device has been developed to examine how pharmaceutical tablets dissolve under conditions very similar to those in the human stomach. For that purpose, Prednisone USP compendial standard tablets were dissolved in two different apparatuses. On one side, a distal gastric simulator, known as the in vitro Distal Gastric Simulator (IV-DGS), was used. This simulator closely replicates the physiological conditions of the human stomach. It can mimic its operating environment, including peristaltic movement at 3 cycles per minute and an average maximum pressure of about 25 mm Hg. The results from the gastric simulator were compared with the dissolution rates measured using the United States Pharmacopeia-approved apparatus 2. The results show that after 12 min, the USP Apparatus 2 achieved 71.5% dissolution, while the IV-DGS reached 24.9%, indicating a slower dissolution rate but a more realistic gastric mixing. The dissolution data from both systems were modeled using a first-order and a Weibull model, with the latter providing a better fit. Although the results are not entirely comparable with USP 2, the gastric simulator offers a much more realistic alternative for in vitro drug dissolution studies.