Bioequivalence and Bioavailability Forum

Hi,

regarding the calculation of concentration of the stock solution, we have esomeprazole magnesium dihydrate,

the potncy on as is basis is 99.2%, when the potency, is given on as is basis, do we need to take in to consideration for the dihydrate during the follwoing calculation?

the standard formula used is:

[weight(g)/Volume(mL)] x [purity (%)/100]x[Molecular weight of free form /Molecular weight of salt form)

in this case, what do we need to consider as the salt form:

1. esomeprazole magnesium dihydrate

or

2. esomeprazole magnesium only?

if the answer is the first one, my question is why do we need to consider the dihydrate, since the potency is on "as is basis" means it would have been calculated by cosnidering the water content.

please share your valuable thoughts.

regards,