1.TITLE
Experiment 5: Content of ibuprofen (assay)
Aim : To determine the content of ibuprofen by using titration.
Date :12/12/2013
2. INTRODUCTION
The content uniformity test is used to ensure that every tablet contains the amount of drug substance intended with little variation among tablets within a batch. Due to increased awareness of physiological availability, the content uniformity test has been included in the monographs of all coated and uncoated tablets and all capsules intended for oral administration where the range of size of the dosage form available include 50mg or smaller sizes. 0.5g of ibuprofen is extracted by chloroform and titrate with sodium hydroxide to determine its content.
3. EXPERIMENTAL METHOD
3.1
Apparatus:
Conical flask, beaker, measuring cylinder, pipette, filter funnel, filter paper, hair dryer
Chemicals:
0.1M sodium hydroxide, 20 Ibuprofen tablets, chloroform, ethanol, phenolphthalein
3.2
Procedures:
1. 20 Ibuprofen tablets previously selected at random were weighed and were powdered.
2. A quantity of powder containing 0.5 g ibuprofen was extracted with 20 ml chloroform for
15 minutes and was filter through a sintered glass crucible (BS Porosity No. 1).
3. The residue was washed with 3 × 10 ml chloroform and the combined
filtrate was gently evaporated just to dryness in a current of air. The residue was dissolved in 100 ml 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 the indicator.
4. RESULTS AND CALCULATIONS
5. DISCUSSION
The results of the experiment is good as the percentage of error is low which is 9.32%.
The are some errors which contribute to percentage of error. One of the errors was the glass apparatus used in the experiment were not cleaned by using distilled water and not dried properly before the experiment start. The apparatus may contain contaminant which affect the experimental result.
Next error was human error. When determine the amount of sodium hydroxide used to titrate ibuprofen, the eye of the observer was not directly proportional to the meniscus of sodium hydroxide, causes result to be inaccurate.
During titration, the sodium hydroxide was dropped too fast into the conical flask containing ibuprofen, excessive amount of sodium hydroxide was dropped. Precaution is to drop the sodium hydroxide drop by drop when the reading near to the theoretical value.
6. CONCLUSION
The content of ibuprofen is uniform in the tablets as the percentage of error for this experiment is low.
7. REFERENCES
4) Aulton, M.E. 2002. Pharmaceutics: The Science of Dosage form Design. Edinburgh Churchill Livingstone
5) Banker, G.S & Rhodes, C.T. 2000. Modern Pharmaceutics. Ed. Ke-2. New York. Marcel Dekker.
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