A mechanical calibration protocol study is currently under way to examine whether mechanical calibration is equal to or better than calibrator tablets. However opinions vary in regards to eliminating or reducing chemical calibrators.
Calibration parameter |
Current USP tolerances |
Point of measurement |
Proposed tolerances |
Proposed frequency |
Height check |
25+-2mm |
Paddle/basket bottom |
25+-2mm |
At time of use if vessels are removed |
Basket wobble |
+-1mm as runout |
Bottom of basket rim |
+-1.0 mm total run out |
Every 3 months |
Rotational speed |
+-4% |
Not applicable |
+-1 rpm |
Every 3 months |
Vessel-shaft centering |
2mm from center line |
Center line |
2mm from center line |
Every 3 months |
Vessel temperature |
37+-0.5C |
Not applicable |
37+-0.5C |
At time of use |
Bath levelness |
Level |
Base plate |
Level |
Every 3 months |
Shaft wobble |
no significant wobble |
2cm above top of paddle blade |
<0.5 mm total run out |
Every 3 months |
Paddle/basket dimensions |
See USP |
See USP |
See USP |
Upon receipt |
Vessel dimensions |
See USP |
See USP |
See USP |
Upon receipt |
Degassing technique |
NCDA2 passes calibration |
Not applicable |
NCDA2 passes calibration |
Once per year |
Proposed parameters under investigation |
|
|
|
|
Paddle/basket examination |
None |
Not applicable |
No gross defects as determined by visual inspection |
At time of use |
|
Shaft verticality |
None |
Above vessel |
Vertical as measured by a bubble level |
Every 3 months |
Visual inspection of belts; check ball bearings |
None |
Not applicable |
Belts are tight, clean, free of cracks, properly aligned; shaft turns freely |
Every 3 months |
|
Vibration |
None |
Base plate while operating at 100 rpm |
<0.2mil |
Every 3 months |
Literature Cited: Pharmacopeial Forum: Volume 26, Number 4