Assessment of a dissolution vessel designed for use with floating and erodible dosage forms

A standard dissolution vessel was modified for the purpose of assessing more reliably the performance of floating dosage forms, particularly those which rely on erosional mechanisms to control drug release rate. The floating dosage form was placed under a supported stainless steel mesh, situated 72 mm from the base of the vessel, and the dissolution test carried out with the paddles set 10 mm above the mesh. The performance of the modified dissolution vessel was explored using two different floating dosage forms; liquid-filled HALO®-propranolol capsules with biphasic rapid and sustained-release characteristics and a rapid-release only floating dosage form consisting of lipidic granule-filled Macrotonin® capsules. In the case of HALO®-propranolol capsules, performance of the novel dissolution vessel was compared with an existing dissolution method for floating dosage forms in which the paddles are set to the surface of the dissolution medium in the vessel, and the use of wire sinkers. The results showed that the modified dissolution vessel provided a more reproducible dissolution profile, eliminated the risk of floating dosage forms adhering to the paddles and simplified sampling procedures, while retaining the ability to differentiate between acceptable and unacceptable dissolution performance.