Calibration-Prednisone Tablet Failures

[Archives]

Poster: Paddle
Date Originally Posted: 12/19/99

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"What could be the cause of one prednisone tablet failing every time the calibration is run?
A tablet will fail in a different vessel each time the test is repeated. "

[Archives]

Poster: Disillusioned
Date Originally Posted: 12/19/99

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"This may be common knowledge to everyone, but it was not to me, so...

I just experienced the same problem - a single, different paddle/vessel failing each time.
The glass vessels were cleaned, all physical parameters were in spec, and the Salicylic
Acid had passed. The Prednisone failures were always with a low result. I suspected the
calibrator tablets, but a new container (same lot) yielded the same result.

I spoke with a chemist at ******, and he informed me that Prednisone dissolution is
extremely sensitive to temperature. The vessel temperatures I was using ranged from
36.5C (vessels 4 and 8) to 36.9C (vessels 1 and 4), which is within the USP
specs/guidelines for Prednisone dissolution. He suggested that I adjust the vessel temps
to at least 37.0C. My vessels then had a range of 37.0C (at the bath outlet) to 37.3C (at
the inlet), again, within USP specs. Sure enough, all the vessels passed.

Moreover, the resulting data was much tighter. The previous 4 runs had yielded RSD's of
4.2, 5.2, 5.7 and 6.0%. The final run which passed had a RSD of 1.7%.

So, to make a long story short, check your vessel temps.


>>> 12/19/99 2:08:41 PM User ""Paddle"" wrote <<<
What could be the cause of one prednisone tablet failing every time the calibration is run?
A tablet will fail in a different vessel each time the test is repeated. "

[Archives]

Poster: DNT
Date Originally Posted: 12/19/99

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"We have experienced a similar problem.

The cure was to clean every vessel thoroughly; ultrasonication in 5% deacon solution and
then thorough rinsing in USP water. Cleaning by hand was not good enough.

Acid cleaning is another alternative, but so far we have avoided it because of the obvious
safety issues.


>>> 12/19/99 2:08:41 PM User ""Paddle"" wrote <<<
What could be the cause of one prednisone tablet failing every time the calibration is run?
A tablet will fail in a different vessel each time the test is repeated. "

[Archives]

Poster: grayva
Date Originally Posted: 12/19/99

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"Is the distribution of the particles unusual in the failing vessels? You could check the belt
out--some times it will slip due to dirt or being too loose, and effect different vessels.
You didn't mention which speed and apparatus.

>>> 12/19/99 2:08:41 PM User ""Paddle"" wrote <<<
What could be the cause of one prednisone tablet failing every time the calibration is run?
A tablet will fail in a different vessel each time the test is repeated. "

[Archives]

Poster: aka
Date Originally Posted: 12/19/99

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"Would you believe a ""calibrator standard"" that fails to meet the normally accepted criteria
of a standard? We should all be glad that the rest of the USP reference standards
perform their function in a more acceptable manner. As long as you have physically set
up the equipment to the USP criteria, and are using a suitable deaeration technique, there
is nothing more that you can do except continue to test until the apparatus passes.

>>> 12/19/99 2:08:41 PM User ""Paddle"" wrote <<<
What could be the cause of one prednisone tablet failing every time the calibration is run?
A tablet will fail in a different vessel each time the test is repeated. "