500 ml Deionized Water
Absorptivity is usually 44-45
Prednisone: a disintegrating tablet. Highly affected by mechanical parameters and vessels. Recently reformulated to be sensitive to poorly deaerated media.
Prednisone, according to the Pharma study, when tested by paddles at 50 RPMs, is operationally sensitive to several perturbations, including: centering, vibration, shaft wobble, shaft verticality, and degassing.
There have been many concerns about the new lot of Prednisone Lot M. Many have stated that their systems that routinely passed, will no longer easily pass. Recently Tahseen Mirza, formerly of the USP, posted suggestions on line. Here are his suggestions to eliminate any problems.
- Clean the dissolution vessels thoroughly- concentrated acid, methanol, soap and de-ionized water
- Make sure that the vessel walls are not scratched.
- Conduct a filtration study to determine if there is adsorption on the filter membrane.
- Use the degassing procedure described in the USP, (Helium sparging might not work it only replaces oxygen with helium.) Do not let the medium sit too long prior to dropping the tablets and do not stir the paddles to accelerate temperature equilibration.
- Check the paddle height and centering before and after the test.
- Check calculations and make sure that the standard is being prepared properly.
Recently one lab wrote in because they had a problem with prednisone calibration. Construction outside of the facility caused infrequent vibration. The construction effect gave higher result of prednisone during calibration
Another lab wrote in because they had been degassing with helium. They suddenly had a problem with prednisone calibration. They switched to vacuum filtration for degassing and all passed perfectly!
Literature cited: Dissolution Technologies November 2000.
Tahseen Mirza, Q+A: http://www.dissolutiontech.com/DTresour/1100ART/1100Q%26A.htm
Do you have any Prednisone tips that you want to post online?