A: Infrared Absorption 197M.

B: Ultraviolet Absorption 197U—

Test solution— Prepare a solution of Triazolam in chloroform containing about 2 mg per mL.

Chromatographic system (see Chromatography 621)— The gas chromatograph is equipped with a flame-ionization detector, and contains a 3-mm × 120-cm glass column packed with 3% phase G6 on support S1AB. The column and injection port are maintained at a temperature of about 240. The detector is maintained at a temperature of about 20 to 50 above column temperature. The carrier gas is helium.

Procedure— [NOTE—Allow about three times the elution time of the major component before making another injection.] Chromatograph about 4 µL of the Test solution. Calculate the total percentage of impurities taken by the formula: in which S is the sum of the areas of each of the minor component peaks detected, and A is the area of the major component peak. The total amount of impurities present is not more than 1.5%.

(Official January 1, 2007)

Mobile phase— Prepare a filtered and degassed mixture of acetonitrile, chloroform, butyl alcohol, water, and glacial acetic acid (850:80:50:20:0.5). Make adjustments if necessary (see System Suitability under Chromatography 621).

Internal standard solution— Dissolve an accurately weighed quantity of alprazolam in acetonitrile, and dilute with acetonitrile to obtain a solution having a known concentration of about 0.3 mg per mL.

Standard stock solution— Dissolve an accurately weighed quantity of USP Triazolam RS in Internal standard solution, and dilute with Internal standard solution to obtain a solution having a known concentration of about 0.25 mg per mL.

Assay stock solution— Transfer about 2.5 mg of Triazolam, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with Internal standard solution to volume, and mix.

Standard preparation— Dilute an accurately measured portion of the Standard stock solution with acetonitrile to obtain a solution having a known concentration of USP Triazolam RS of about 0.025 mg per mL.

Assay preparation— Transfer about 5 mL of the Assay stock solution, accurately measured, to a 50-mL volumetric flask, dilute with acetonitrile to volume, and mix.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 30-cm column that contains packing L3. The flow rate is about 2.0 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed under Procedure: the relative retention times are 1 for triazolam and about 1.4 for the internal standard, the resolution, R, between the internal standard and triazolam is not less than 2.0, and the relative standard deviation for replicate injections is not more than 2.0%.

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 stock solution; V is the volume of internal standard used to prepare the Assay stock solution; and RU and RS are the ratios of the internal standard peak area to the alprazolam peak area obtained from the Assay preparation and the Standard preparation, respectively.