ASSAY OF CLOPIDOGREL BISULPHATE BY HPLC METHOD

Preparation of phosphate buffer solution : Dissolve 2.72gms of monobasic potassium phosphate in about 500ml of water and dilute to 1000ml with same solvent. Adjust pH to 6.0 ± 0.1 with KOH.

Mobile Phase :  Prepare a filtered and degassed mixture of Phosphate Buffer and acetonitrile (35:65) .Make adjustment if necessary.

Standard Preparation : Dissolve 50mg 0f Clopidogrel Bisulphate Working Standard in methanol, sonicate and make volume to 50ml with methanol.Dilute 5ml of solution to 50ml with mobile phase (conc.0.1mg/ml). Filter the solution with 0.22µm before injection.

Assay Preparation : Crush finely 20 tablets into powder and weigh an amount of powder containg 100mg of Clopidogrel Bisulphate in a 100ml volumetric flask . Dissolve the content with methanol, sonicate and dilute with methanol to volume and mix, filter. Pipette 5ml of this solution to a 50ml volumetric flask, dilute with mobile phase to volume and mix.

Chromatographic System :

Column                  : 4.6mm x 25cm column that contains packing L1

Flow rate              : 1.5ml /min

Wavelength          : 265nm

Temperature                  : Ambient

Injection volume   : 20µL

The relative standard deviation (RSD) for replicate injections determined from Clopidogrel Bisulphate is not more than 1.0% .

Procedure :

Seperately inject equal volumes (about 10µL) of the standard preparation and the assay preparation into the chromatograph ,record the chromatograms, and measure the areas for all peaks . Calculate the quantity in mg of C₁₆H₁₆ClN0₂S.H₂S0₄ in

The portion of the tablet taken by the formula :

                                          Peak area of sample     Wt.of sample

% of Clopidogrel Bisulphate :------------------------X  --------------------X Potency of WS

                                           Peak of standard        Wt.of standard      

Where :  WS is the Working Standard .