Calculation on as such basis & anhydrous basis OR Potency calculation of an active drugs substance

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.

CALCULATI ON 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.