Assay Calculation

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Gamalmostafa
Gamalmostafa's picture
Assay Calculation

I have a problem in assay calculation. where I analyse hard gelatin capsule of Amoxicillin. the capsule contains 266 mg of Amoxicillin Trihydrate equivlaent to 250mg of amoxicillin. I use the following equation.
mg/cap = A t x W s( mg) x Dfu x P x Av. Fill Wt. of cap.
A s x Dfs x W t (mg) x 100
where
A t : the response of test solution.
A s : the response of standard solution.
Dfu : the dilution factor of test solution.
Dfs : the dilution factor of standard solution.
W t & W s : the weigh of Test and standard respectively.
P : is the purity of amoxicillin standard.( here is the problem)
where I have two assay of Amoxicillin working standard one is [b]AS SUCH ( 85.9%) and ON DRY BASIS 98.8%) my question here when I use ON DRY BASIS potency should I have the result of mg/cap as amoxicillin base or WHAT???
Provided that the USP does not recommend drying the standard of Amoxicillin trihydrate).
Please can you help

Srinivasareddy....
Srinivasareddy.Attunuri's picture
If u are taking warking

If u are taking warking standard as is basis result is ammoxacilin base

If u are taking warking standard on dried basis result is ammoxacilin

Ajesh
Ajesh's picture
Nice Question.

Nice Question.

As we have to find the content of amoxicillin trihydrate equivalent to Amoxicillin in mg per capsule of av.net.weight we have to use as such ie 85.9% for standard purity in calculation because rest of the percentage ,ie 14% may be of water molecule(as the R.S amoxicillin in its trihydrate form)

bUJJI
bUJJI's picture
Potency is always As such

Potency is always As such unless and otherwise specified. Potency on dried basis should not be considered. since You are getting the area of amoxicillin but not for LOD/WATER by HPLC. you have the absorbance for 85.9% potency.

Rajeshwari patel
Rajeshwari patel's picture
Nice quation.

Nice quation.

If you are going to report your potency report on basis of Iu/mg you take  85.9% and if you want to report in IU/cap you take according to that be cause youar measuring replative potency which is coimng according to your standrd which you take for the estimation.

Durga Nautiyal
Durga Nautiyal's picture
If in Pharmacopia is not

If in Pharmacopia is not specifying wether value is calculated on As Such Basis OR On Anhydrous Basis then, which calculation we will used (As Such Basis OR On Anhydrous Basis).

Rajeshwari patel
Rajeshwari patel's picture
hi,

hi,

in this case you assy range unit is what ?  Iu? mg?please explain

Durga Nautiyal
Durga Nautiyal's picture
Hello Raj ji,

Hello Raj ji,
 
Actually this regarding the test chloride content i.e in IP limit is mentioned 5.0-5.5%w/w, but they are not specifying wether the specs is on As Such Basis OR On Anhydrous Basis.

Regrads
Durga
 

aswini nalamalapu
aswini nalamalapu's picture
I HAVE A PROBLEM IN POTENCY

I HAVE A PROBLEM IN POTENCY CALCULATION, difference between assay on dried basis, assay on as is basis and assay on anhydrous basis?
when we can calculate ssay on dried basis, assay on as is basis and assay on anhydrous basis?

aswini nalamalapu
aswini nalamalapu's picture
I HAVE A PROBLEM IN POTENCY

I HAVE A PROBLEM IN POTENCY CALCULATION, difference between assay on dried basis, assay on as is basis and assay on anhydrous basis?
when we can calculate ssay on dried basis, assay on as is basis and assay on anhydrous basis?

amirali2820
amirali2820's picture
 i want to calculation p

 i want to calculation p[otency for erythromycin ethyl succinate 

pls help me to have calculation method and formula and sampl of calculateion

thanks alot