CyberWorld

The validity check on the label claim of an off the counter drug like Ibuprofen proves to be an exciting but simple project. It helps the student understand the nature of a carboxylic group, the quantitative determination of the drug based on the number of carboxylic groups through a simple acid base titration. Ibuprofen is made up of covalently-bonded carbon, hydrogen, and oxygen atoms. 2 CH3 molecules are single-bonded to a CH molecule. The CH molecule, is bonded to a carbon atom that forms a 6-sided ring of carbon atoms. Another CH molecule is single-bonded to a carbon atom on the other side of the ring. Inside the ring there are 3 double bonds between carbon atoms.

Then another CH3 molecule and a COOH molecule are both single bonded to the CH molecule on the right. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) which is commonly used for relieving muscular and skeletal pain. Ibuprofen is a white powder belonging to the propionic acid derivatives, with a melting point of 74 - 77° C. It is only slightly soluble in water but readily soluble in organic solvents such as ethanol. Ibuprofen acts so as to inhibit the action of the enzyme cyclooxygenase, which catalyses the transformation of fatty acids to prostaglandins. Thus the synthesis of prostaglandin is inhibited and this is the cause for the analgesic and anti-inflammatory action of the drug. Because it is non-steroidal, it is widely used as it does not upset the hormonal balance in the body.

Its anti-inflammatory, analgesic (pain relieving) and antipyretic (fever reducing) actions, are comparable to those of aspirin and it is commonly taken in tablet form for the relief of mild to moderate pain such as headache, toothache, and migraine as well as symptoms of fever. Ibuprofen tablets are very useful for relieving signs and symptoms of rheumatoid arthritis and osteoarthritis, to reduce joint swelling and improves the action of joints. It is used to relieve postoperative pain and morning stiffness and has also been shown to slow down pulmonary decline in cystic fibrosis sufferers. Since Ibuprofen is available for over-the-counter sale, the label claim for the amount of drug in each tablet is of importance.

The Ibuprofen tablets are weighed, crushed and a known amount is solubilized to prepare a standard 100ml solution of known concentration. If the added fillers and additives interfere, the solution is filtered. A known aliquot of ibuprofen solution is titrated against a standard solution of sodium hydroxide using phenolphthalein as an indicator. For most of the experiments tablets of reputed pharmaceutical as well as generic drugs closely match the label claim.

Acknowledgments- The experiments to validate the label claim of Ibuprofen were carried out by Sheryl Fernandes and Cynthia Jeyakumar of Grade XII of R.N. Podar CBSE Sr. Secondary School, Santacruz (W).