Method and apparatus for dissolution testing of a dosage form

An apparatus for testing dissolution of a swellable, floatable dosage form comprising:

• an inert, transparent cylindrical vessel adopted to hold a fluid medium having a hemispherical concave bottom;
• a stirring mechanism having a vertical shaft adapted to depend into the fluid medium and a blade at a lower end of the shaft for rotating the fluid medium;
• and
• a disk positioned in the vessel spaced from the vessel bottom, the disk comprising a pair of annular rings adapted to engage the vessel and a screen mesh circumferentially sandwiched by the rings to allow passage of the fluid medium through the disk screen mesh;
• a dosage form retaining space defined by the volume intermediate to the disk and the vessel bottom for containing the dosage form.

A method for testing the dissolution of a drug from a dosage form comprising:

• providing an inert cylindrical vessel having a hemispherical concave bottom containing a fluid medium;
• placing the dosage form in the vessel;
• inserting a disk into the vessel which engages the vessel wall at a location above the dosage form, thereby forming a dosage form retaining space for retaining the dosage form in the fluid volume under the disk, the disk having a plurality of holes for passage of the fluid medium therethrough;
• inserting a stirring mechanism having a vertical shaft and a blade at a lower end of the shaft into the vessel;
• rotating the stirring mechanism to circulate the fluid medium in the vessel;
• sampling the drug concentration in the fluid medium at selected time intervals.

In combination an apparatus and dosage form for testing of the dosage form, the combination comprising:

• an inert cylindrical vessel adapted to hold a fluid medium having a bottom, a stirring mechanism depending into the vessel for rotating the fluid medium, and a disk positioned in the vessel adapted to engage the vessel wall at a location spaced from the vessel bottom, the disk having a plurality of holes for passage of the fluid medium therethrough;
• a swellable, floatable dosage form adapted for three dimensional swelling and a drug release over a specific period of time;
• and
• a dosage form retaining space defined by the volume intermediate to the disk and the vessel bottom for retaining and allowing floating and swelling of the dosage form between the vessel bottom and the disk.