Medium: water; 500 mL.

Apparatus 2: 50 rpm.

Time: 30 minutes.

Stock standard solution— Weigh accurately about 5 mg of USP Triazolam RS, dissolve in and dilute with methanol to 200.0 mL, and mix.

Working standard solution— For each 0.125 mg of the labeled amount of triazolam per Tablet, add 2.0 mL of Stock standard solution to a 200-mL volumetric flask. Dilute with water to volume, and mix.

Procedure— After 30 minutes, withdraw a portion of the solution under test, and filter immediately. Inject equal volumes (about 200 µL) of this solution and the Working standard solution into a liquid chromatograph (see Chromatography 621) equipped with a detector capable of monitoring UV absorbance at 222 nm and a 4.6-mm × 10-cm stainless steel column containing packing L7. The mobile phase is a mixture of water and acetonitrile (60:40). The flow rate is about 1 mL per minute. The relative standard deviation of the peak response for the Working standard solution is not more than 3.0%, and the number of theoretical plates is not less than 500. Calculate the percentage of C17H12Cl2N4 dissolved by the formula: in which rU and rS are the peak responses of the solution under test and the Working standard solution, respectively, C is the concentration, in mg per mL, of USP Triazolam RS in the Working standard solution, and L is the labeled amount, in mg, of triazolam in the Tablet.

Tolerances— Not less than 70% (Q) of the labeled amount of C17H12Cl2N4 is dissolved in 30 minutes.

Procedure for content uniformity—

Mobile phase and Chromatographic system—Proceed as directed in the Assay under Triazolam.

Internal standard solution— Prepare a solution of alprazolam in acetonitrile having a concentration of about 0.025 mg per mL.

Standard preparation— Dissolve about 3.2 mg of USP Triazolam RS, accurately weighed, in 100.0 mL of Internal standard solution, and mix.

Test preparation— Transfer 1 Tablet to a container, add about 0.4 mL of water directly onto the Tablet, allow to stand for about 2 minutes, and swirl the container to disperse the Tablet. For each 0.25 mg of the labeled amount of triazolam in the Tablet, add 10.0 mL of Internal standard solution to the container. Shake, and centrifuge if necessary.

Procedure— Proceed as directed for Procedure in the Assay under Triazolam. Calculate the quantity, in mg, of C17H12Cl2N4 in the Tablet taken by the formula: in which V is the volume, in mL, of Internal standard solution in the Test preparation.

(Official January 1, 2007)

Mobile phase and Chromatographic system—Proceed as directed in the Assay under Triazolam.

Internal standard solution— Prepare a solution of alprazolam in acetonitrile, having a concentration of 0.1 mg per mL.

Standard stock solution— Dissolve an accurately weighed quantity of USP Triazolam RS in acetonitrile, and dilute with acetonitrile to obtain a solution having a known concentration of about 0.1 mg per mL.

Standard preparation— Transfer 8.0 mL of Standard stock solution to a 200-mL volumetric flask, add 8.0 mL of Internal standard solution, dilute with acetonitrile to volume, and mix.

Assay preparation— Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed quantity of the powder, equivalent to about 0.8 mg of triazolam, to a 200-mL volumetric flask. Add 2 mL of water, mix, and allow to stand for 10 minutes. Mix vigorously for 10 seconds, and add 8.0 mL of Internal standard solution, shake vigorously for 10 minutes, dilute with acetonitrile to volume, and mix.

Procedure— Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the area responses for the major peaks. Calculate the quantity, in mg, of C17H12Cl2N4 in the portion of Triazolam taken by the formula: in which C is the concentration, in mg per mL, of USP Triazolam RS in the Standard preparation, and RU and RS are the ratios of the internal standard peak area to the triazolam peak area obtained from the Assay preparation and the Standard preparation, respectively.