Identification of Mefenamic Acid

Molecular Formula: C15H15NO3  

Molecular Mass M.wt =241.3 g /mol

Chemical Name: Mefenamic acid [2-(2,3-dimethyl phenyl)amino]benzoic acid

General Requirement: Mefenamic acid contains not less than 95.0% and not more than 105.0% of C15H15NO3 , calculated with reference to the dried substance

Materials Required

        Mefenamic acid Tablate

       Sodium hydroxide Solution......................... 0.1N 

Phenol Red indicator 

Principle

Mefenamic acid is an example of Non-Steroidal anti-inflammatory drug. It is also having analgesic and antipyretic activity. It is widely used in the management of pain and fever. Mefenamic acid is weakly acidic in nature and therefore can be estimated by alkalimetry. Alcoholic solution of Mefenamic acid is titrated against 0.1N NaOH solution using phenol red indicator .The reaction involved are as follows

Procedure

Weight accurately, about 0.25gm of Mefenamic acid and dissolve in 25ml of neutralised methanol.

Titrate the contents against 0.1N sodium hydroxide solution using phenol Red indicator

Equivalent Factor

Each ml of o.1N NaOH = O.O2413 gm of Mefenamic acid

From the volume of the 0.1N NaOH consumed, Calculate the amount of Mefenamic acid present in the given sample solution

    Another Method

  Assay

Weigh accurately about 0.5 g of Mefenamic acid. Previously dried, and dissolve in 100 ml of ethanol (95%). Previously neutralized to phenol red TS with

0.1  M sodium hydroxide VS, by warming gently. Cool, and titrate with 0.1 M Sodium hydroxide VS until the color of the solution changes from yellow through yellow-red to red-purple(indicator :2 to 3 drops of phenol red TS)Perform a blank determination, and make any necessary correction

Each ml of 0.1 M NaOH ≡ 24.129 mg of C15H15NO3

للتقرير انقر هنا to report