HOW TO CALCULATE THE ACTIVE INGREDIENT CONTENT IN A GALENIC FORM?

Calculation for Lindilane® 10 mg/mL:

The calibration line gives experimental values for the concentration of the galenic form (GF).

 [GF] = 7.97 mg/L
  The experimental value is 7.97 mg of paracetamol per liter for a test sample of 50 mg of tablet powder. However, the 50 mg tablet powder includes 40 mg active ingredient, the remainder being codeine and excipients.

The calculation is as follows:
A concentration of 7.97 mg/L is found instead of the expected 8 mg/L (cf. protocol at the beginning of the animation). By increasing the dilution to the 1/100° initially achieved, the experimental concentration of the GF stock solution is obtained:

7.97 x 100 = 797 mg/L meaning 39.85 mg in the initial 50 mL of solvent.

When considering the test sample again, we therefore have 39.5 mg out of the 40 mg of paracetamol expected in the 50 mg of tablet powder of the test sample.

Considering a 500 mg Lindilane tablet, 395 mg of paracetamol is obtained instead of the expected 400 mg.
This batch complies with the range specified by the manufacturer (+ or – 5%, meaning 380-420 mg paracetamol in a tablet)