Apparatus 6 (Cylinder)
Use the vessel assembly as described in Dissolution á711ñ, Apparatus, Apparatus 1 (Basket Apparatus), except replace the basket and shaft with a stainless steel cylinder stirring element with the specifications shown in Figure 3. This cylinder stirring element is composed of two parts, one comprising the shaft and the upper cylinder, and the other being the extension cylinder.
Since both parts are serially numbered, it is recommended that they be kept paired because the friction fitting is done individually for each cylinder, allowing a very tight fit. The distance between the inside bottom of the vessel and the cylinder is maintained at 25 ± 2 mm during the test.
Figure 3. Cylinder stirring element.
(All measurements are expressed in cm unless noted otherwise.)
MEDIUM
See Dissolution Medium in Dissolution á711ñ, Procedure, Apparatus 1 and Apparatus 2, Immediate-Release Dosage Forms.
PROCEDURE
Place the stated volume of Medium in the vessel, and equilibrate to 32 ± 0.5°.
Apply the TDS to the cylinder, assuring that the release surface is as smooth as possible and the TDS is completely and firmly attached to the cylinder. The TDS, with release side facing the Medium, may be attached to the cylinder by an appropriate and validated procedure such as use of an adhesive, double-face adhesive tape, membrane, or nylon net. Care must be taken to avoid the presence of air bubbles between the membrane, if used, and the TDS, or the presence of wrinkles on the surface of the TDS. Carefully remove the protective liner from the TDS without causing damage to the surface. If additional reinforcement of the TDS to the cylinder is needed, inert metal wire or a polymer ring may be used.
Place the cylinder in the apparatus, and immediately rotate at the rate specified in the individual monograph. The vessel may be covered during the test to minimize evaporation.
At each sampling time interval, withdraw a specimen from a zone midway between the surface of the Medium and the top of the rotating cylinder, not less than 1 cm from the vessel wall.
Perform the analysis on each sample aliquot as directed in the individual monograph, correcting for any volume losses, as necessary. Repeat the test with additional TDS, as needed.
TIME
The test time points, at least three, are expressed in hours. Specimens are to be withdrawn within a tolerance of ±15 min or ±2% of the stated time, selecting the tolerance that results in the narrowest time interval.
INTERPRETATION
Unless otherwise specified in the individual monograph, the requirements are met if the quantities of active ingredient released from the system conform to Acceptance Table 1 above. Continue testing through the three levels unless the results conform at either L1 or L2.
