CLOPIDOGREL 75 mg + ASPIRIN 81 mg

Dissolution

For Clopidogrel (by HPLC)

Dissolution parameters:

Potassium chloride solution: Dissolve 14.91 g of potassium chloride in 1000 ml of water.

Preparation of pH 2.0 hydrochloric acid buffer: Take 250 ml of potassium chloride solution in 1000 ml volumetric flask, add 65 ml of hydrochloric acid and make up the volume to 1000 ml with water.

Medium: pH 2.0 hydrochloric acid buffer, 1000 ml.

Apparatus: 2 (Paddle)

Speed: 50 rpm.

Run time: 30 minutes.

Dissolution procedure:

1. Set dissolution apparatus by programming temperature, rotation and run time at 37°C±0.5°C, 50 rpm and 30 minutes respectively.
2. Place 1000 ml of dissolution medium into each of the six vessels of the dissolution apparatus.
3. Assemble the apparatus and equilibrate the dissolution medium at 37°C±0.5°C.
4. Place one tablet into each of six vessels and allow the tablet to the bottom of the vessels before starting the rotation of the paddles.
5. Immediately start the rotation of the paddles at the speed of 50 rpm for 30 minutes.

                                   Note: Keep the vessel covered during the test.

• After 30 minutes, withdraw the 10 ml aliquots from a zone midway between the surface of the dissolution medium and top of the paddles, from each of six vessels.

Test solution: After 30 minutes, collect the sample individually from vessels and filter.

Take 5 ml of the filtrate to 10 ml volumetric flask and make up the volume to 10 ml with mobile phase.

Standard solution: Dissolve an accurately weigh about 98 mg of Clopidogrel Bisulfate RS or Clopidogrel Bisulfate WS into a 100 ml volumetric flask and add about 50 ml methanol and shake until dissolve then dilute with methanol to 100 ml and filter.

Take 5 ml filtrate to 100 ml volumetric flask and make up the volume to 100 ml with mobile phase.

Buffer: Dissolve about 1.36 g monobasic potassium phosphate in 1000 ml of water.

Mobile phase preparation: Acetonitrile and buffer (60:40).

Chromatographic conditions:

Mode: LC.

Detector: UV 220 nm.

Column: C08 (4.6 mm x 25 cm).

Flow rate: 1.5 ml/ml.

Injection volume: 20 µl.

Procedure: Separately inject equal volumes (about 20 µl) of the Standard preparation and the test preparation into the chromatograms, and measure the responses for the analyte peaks.

System suitability:

Sample: Standard preparation.

Suitability requirements:

Relative standard deviation: NMT 2.0%.

Calculation: Calculate the content of Clopidogrel (C₁₆H₁₆CINO₂S) in percent, by given below formula:

             Test area             Std. dilution        Potency (in %)

  —————————× ——————–×————————× Conversion factor (0.7664) x 100.

    Average Std. area        Test dilution              100

For Aspirin (by HPLC)

Dissolution parameters:

Preparation of 0.05 M Acetate Buffer solution: Mixing 2.99 g of Sodium acetate trihydrate and 1.66 ml of glacial acetic acid with water to obtain 1000 ml of solution having a pH 4.50 ± 0.05.

Medium: 500 ml of 0.05 M Acetate Buffer pH 4.50 ± 0.05.

Apparatus: (1) Basket.           

Speed: 50 rpm.

Run Time: 30 minutes.

Dissolution procedure:

1. Set dissolution apparatus by programming temperature, rotation and run time at 37°C±0.5°C, 50 rpm and 30 minutes respectively.
2. Place 500 ml of dissolution medium into each of the six vessels of the dissolution apparatus.
3. Assemble the apparatus and equilibrate the dissolution medium at 37°C±0.5°C.
4. Place one tablet into each of six vessels and allow the tablet to the bottom of the vessels before starting the rotation of the baskets.
5. Immediately start the rotation of the baskets at the speed of 50 rpm for 30 minutes.

                                   Note: Keep the vessel covered during the test.

• After 30 minutes, withdraw the 10 ml aliquots from a zone midway between the surface of the dissolution medium and top of the baskets, from each of six vessels.

Buffer solution: Dissolve about 2.0 g of sodium 1-heptanesulfonate in a mixture of 850 ml of water and 150 ml of acetonitrile and adjust with glacial acetic acid to a pH of 3.4.

Diluting solution: Prepare a mixture of acetonitrile and formic acid (99:1).

Test solution: After 30 minutes, collect the sample individually from vessels and filter with 0.45 µm filter.

Take 5 ml of the filtrate to 10 ml volumetric flask and make up the volume to 10 ml with diluting solution.

Standard solution: Weigh accurately about 81 mg of Aspirin WS and transfer into a 100 ml volumetric flask and add 70 ml diluting solution and Sonicate about 10 minutes to dissolve and make up the volume to 100 ml with diluting solution and filter.

Take 5 ml filtrate to 50 ml volumetric flask and make up the volume to 50 ml with diluting solution.

Chromatographic conditions:

Column: 30 cm x 3.9 (5 µm) packing L1.

Flow rate: 1.5 ml per minute.

Detection wavelength: 280 nm.

Injection volume: 10 µl.

Procedure: Separately inject equal volumes (about 10 µl) of the blank, five replicate injections of standard preparation and the test solution, record the chromatograms and measure the responses for the analyte peaks.

System suitability: The relative standard deviation for replicate injections is not more than 2.0%.

Calculation: Calculate the content of Aspirin (C₉H₈O₄) in percent, by using given below formula:

            Test area              Std. dilution         Potency (in %)

  —————————× ——————–× ———————-× 100.

    Average Std. area        Test dilution              100