A: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, both relative to the internal standard, as obtained in the Assay.

B: Transfer a portion of the Capsule contents, equivalent to about 50 mg of temazepam, to a 25-mL volumetric flask, add 10 mL of methanol, shake by mechanical means, and allow to settle. Use the supernatant layer as the test solution. Separately apply 20 µL of the test solution and 20 µL of a Standard solution of USP Temazepam RS in methanol containing 5.0 mg per mL to a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture. Place the plate in a chromatographic chamber, and develop the chromatogram in a solvent system consisting of a mixture of toluene, dioxane, methanol, and ammonium hydroxide (65:30:5:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, air-dry, and examine the plate under short-wavelength UV light: the RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.

Sodium acetate buffer— Dissolve 2 g of sodium hydroxide in 450 mL of water in a 1-liter volumetric flask. Adjust with acetic acid to a pH of 4.0, dilute with water to volume, mix, and deaerate.

Medium: Sodium acetate buffer with 0.05% polysorbate 80; 900 mL.

Apparatus 2: 75 rpm.

Time: 30 minutes.

Tolerances— Not less than 80% (Q) of the labeled amount of C16H13O2N2Cl is dissolved in 30 minutes.

Buffer solution, Mobile phase, Internal standard solution, Standard preparation, Chromatographic system, and Procedure— Proceed as directed in the Assay under Temazepam.

Assay preparation— Weigh the contents of not less than 20 Capsules, and calculate the average weight per Capsule. Mix the combined contents, and transfer an accurately weighed portion of the Capsule contents, equivalent to about 40 mg of temazepam, to a 200-mL volumetric flask, add 150 mL of Internal standard solution, and shake the mixture by mechanical means for 30 minutes. Dilute with Internal standard solution to volume, and mix. Allow the contents of the flask to settle, and filter, discarding the first 5 mL of the filtrate.