ASSAY
Calculation on as such basis & anhydrous basis
EXAMPLE :
Assay of dexamethasone sodium phosphate on anhydrous basis is =99.96%
And LOD is =3.5 %
NOTE : these above values are given in COA of dexamethasone sodium phosphate.
Then
How to find F (factor)
EXAMPLE
Here we must know about molecular weight of dexamethasone sodium phosphate is = 516.41 g/mol
And molecular weight of dexamethasone phosphate is = 472.446 g/mol
1 gm of dexamethasone phosphate is equivalent to
So 1.1 gm of dexamethasone sodium phosphate is equivalent to 1 gm of dexamethasone phosphate.
CALCULATION OF ACTUAL QUANTITIY OF AN ACTIVE MATERIAL FOR A BATCH MANUFACTURING
Here actual quantity of an active material required to manufacture a batch is calculated using the following formula
Here F = factor = 1.036
Label claim of dexamethasone sodium phosphate is 4.4 mg/ml
Batch size is = 120 litre
So 0.547 gm of dexamethasone sodium phosphate is required to make a 120 litre of batch.
Note - Sometimes overages also taken to make the result upto 100% so the percent of overages is depend on the particular active material.
If we take 3% overages
Then
So a total sum of 547 + 16.41 = 563.41 gm of dexamethasone is taken for a batch size of 120 litre.