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Hi Sesame,
It's 15 years since my days at university, so I hope my memory still serves me well
Given the information you have provided, the calculation below would be correct (94.6% is the potency for atorvastatin AS IS)....46.9 mg of your standard for 44.4 mg of atorvastatin
However, according to our experince with atorvastatin calcium only (not trihydrate), the atorvastatin standard is HIGHLY hygroscopic and therefore, we measure the water content by Karl-Fischer weekly (and water content has increased dramatically in some cases...a few %).
Therefore, the potency of 94.6% declared on your CoA might not be completely correct.
Cheers
Marko
It's 15 years since my days at university, so I hope my memory still serves me well
Given the information you have provided, the calculation below would be correct (94.6% is the potency for atorvastatin AS IS)....46.9 mg of your standard for 44.4 mg of atorvastatin
❝ No way. If the potency is 94.6%, more should be weighed in in order to compensate to 100%, not less: 44.4 mg / 0.946 = 46.9 mg.
However, according to our experince with atorvastatin calcium only (not trihydrate), the atorvastatin standard is HIGHLY hygroscopic and therefore, we measure the water content by Karl-Fischer weekly (and water content has increased dramatically in some cases...a few %).
Therefore, the potency of 94.6% declared on your CoA might not be completely correct.
Cheers
Marko
Complete thread:
- potency sesame 2010-11-01 19:14
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- I was wrong ;-) Helmut 2010-11-06 18:18
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Ing. Helmut Schütz