PRACTICAL V : CONTENT OF IBUPROFEN

TITLE

Content of ibuprofen (assay)

OBJECTIVE

To determine and verify the amount of active ingredient of ibuprofen per tablet.

INTRODUCTION

The assay is to determine and verify the exact amount of the active ingredient of ibuprofen per tablet. 20 ibuprofen tablets were selected at random to identify the exact amount of the active ingredient per tablet.

METHODLOGY

i)        Apparatus and materials

20 tablets of ibuprofen, 100ml of ethanol, phenolphthalein, 0.1M sodium hydroxide, chloroform, mortar , dryer, burette , conical flasks , filtrate paper and filter funnel.

ii)       Procedure

1. 20 ibuproven tablets are crunched and weighted.

2. A quantify of powder containing 0.5g ibuproven was extracted with 20ml chloroform for 15 minutes and filtered through a sintered glass crucible (BS Porosity no 1).

3. The residue was being washed 3 x 10 ml of chloroform and gently evaporate the combined filtrate just to dryness in a current of air. The residue was dissolved in 100ml with ethanol (96 %) previously neutralized to phenolphthalein solution.

4. The solution was titrated with 0.1M sodium hydroxide to end point with phenolphthalein solution as indicator.

RESULT AND CALCULATION

Weight of 20 ibuprofen : 8.2269 g

Each ibuprofen tablet contain 200mg

20 ibuprofen x 200 mg = 4000mg or 4g

Total weight of powder required = (0.5 g x 8.2269 g) / 4 g

                                                            = 1.028 g

Theoretically 1.028g contain of 0.5 g of ibuprofen

Volume of 0.1M sodium hydroxide (end point) = 21.7ml

Thus, 21.7 ml x 0.02063 g of C13H802 = 0.4477 g

DISCUSSION

     After being titration, 21.7ml of sodium hydroxide turn the solution of ethanol with the residue to light purple. Each ml of 0.1M sodium hydroxide is equivalent to 0.02063 g of C13H802.  Thus, 21.7 ml  is equivalent to 0.4477 g of C13H802.  However, the exact amount is 0.5 g.  This is due to several errors that occurred during the experiment.

     Firstly, error occurred during the crunching of the tablets which the powders are out from the mortar since the size of the mortal was small. This will reduce the exact amount of the active ingredient in the powder.

     Secondly, error occurred during the extraction and washing with chloroform. The conical flask did not been clean properly which left the residue in the flask that might be the active ingredient, ibuprofen.

CONCLUSION

Assay will determine the amount of the active ingredient in the tablet. To avoid the errors, bigger size of mortar is required to avoid the powder out from the mortar and make sure the conical flask is being wash properly so that all the residue being filtered and dry to get the exact amount of active ingredient.

REFERENCE

http://www.newdruginfo.com/pharmacopeia/usp28/v28230/usp28nf23s0_m39890.htm