Percent monomer
Mobile phase
Dissolve 34.84 g of arginine, 158.56 g of ammonium sulfate, and 100 mL of isopropyl alcohol in water, and dilute with water to 1000 mL. Adjust with phosphoric acid to a pH of 7.3, degas, and pass through a 0.45-µm porosity filter. Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard solution
Dissolve an accurately weighed quantity of
USP Alteplase RS in water to obtain a solution having a known concentration of about 1 mg per mL.
Test solution
Dissolve an accurately weighed quantity of Alteplase for Injection in water to obtain a solution having a concentration of about 1 mg per mL.
Resolution solution
Prepare a solution containing 1 mg per mL of each of chicken ovalbumin and bovine gamma globulin.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 280-nm detector and a 7.5-mm × 30-cm column that contains packing L25. The flow rate is between 0.5 and 1.0 mL per minute. Chromatograph the
Resolution solution, and record the peak responses as directed for
Procedure: the resolution,
R, between gamma globulin and ovalbumin is not less than 1.6. Chromatograph the
Standard solution, and record the peak responses as directed for
Procedure: the column efficiency determined from the alteplase peak is not less than 1200 theoretical plates.
Procedure
Separately inject equal volumes (about 50 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percent monomer in the portion of Alteplase for Injection taken by the formula:
100(rm / rS),
in which
rm is the peak response for the alteplase monomer, and
rS is the sum of the responses of all of the alteplase related peaks: not less than 95.0% is found.