Percentage stated content of Paracetamol tablet

How to calculate the percentage stated content of sample Paracetamol tablet?

Assay;

  1. 20 tablets of Paracetamol (500mg) taken and crushed into powdered form.
  2. Tablet powder containing 0 .61g is shaken with 300ml of .05M acetic acid.
  3. The extract is then made up to 500ml with 0.05M acetic acid.
  4. The absorbance of the diluted extract is measured at 271nm.
  5. The A (1%, 1cm) value at 257 is 715.

Supposed calculation:

Weight of 20 tablets    = 11.49g

Powder taken (equivalent) = 11.49/20 = 0.57

Absorbance                    =1.462

Expected Content in tablet powder taken:

= wt. of powder taken/wt. of 20 tab x stated content x No. of tablets.

=0.57/11.49 x 500 x 20

=496.08mg

Dilution factor = 50

Calculated Content in tablet powder taken:

Concentration in diluted tablet extract = A/A1%, 1cm

                                    =1.462/715 =0.002g/100ml =2.04mg/100ml

Concentration in original tablet extracts = 2.04 x D.F =2.04 x 50 =102mg/100ml

Volume of original extract    = 500ml

So, amount in original extract= 102 x 5= 510mg

Percentage of stated content = Calculated/Expected x 100  

=510/496.08 x 100 =102%

So, the percentage stated content of sample Paracetamol tablet is 102%

 

Abid Ali @abidaliphm

Doctor of Pharmacy

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s