Temazepam Capsules

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Temazepam Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of temazepam (C₁₆H₁₃O₂N₂Cl).

[CAUTION—Temazepam is a potent sedative: its powder should not be inhaled.]

2 IDENTIFICATION

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

B. THIN-LAYER CHROMATOGRAPHY

Standard solution: 5 mg/mL of USP Temazepam RS in methanol

Sample solution: Transfer a portion of 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.

Chromatographic system

(See Chromatography 〈621〉, Thin-Layer Chromatography.) Mode: TLC

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture Application volume: 20 µL

Developing solvent system: Toluene, dioxane, methanol, and ammonium hydroxide (65:30:5:1)

Analysis: Develop the chromatogram 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.

Acceptance criteria: The R value of the principal spot of the Sample solution corresponds to that of the Standard solution.

3 ASSAY

PROCEDURE

Buffer: 2.7 g/L of monobasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 3.0. Mobile phase: Acetonitrile and Buffer (47:53)

Internal standard solution: 0.2 mg/mL of benzophenone in a mixture of methanol and water (9:1) Standard solution: 0.2 mg/mL of USP Temazepam RS in Internal standard solution

Sample solution: Nominally 0.2 mg/mL of temazepam in Internal standard solution, from the weighed and mixed contents of NLT 20 Capsules. Shake mechanically for 30 min. Allow the contents of the flask to settle, and then filter, discarding the first 5 mL of the filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.) Mode: LC

Detector: UV 254 nm

Column: 4-mm × 25-cm; packing L16 Flow rate: 2 mL/min

Injection volume: 10 µL

System suitability

Sample: Standard solution

[NOTE—The relative retention times for temazepam and benzophenone are about 1.0 and 2.0, respectively.]

Suitability requirements

Resolution: NLT 1 between the temazepam peak and any other peak Column efficiency: NLT 800 theoretical plates

Tailing factor: NMT 2

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of temazepam (C H O N Cl) in the portion of Capsules taken:

Result = (R /R ) × (C /C ) × 100

= peak response ratio of temazepam to the internal standard from the Sample solution

= peak response ratio of temazepam to the internal standard from the Standard solution

= concentration of USP Temazepam RS in the Standard solution (mg/mL)

= nominal concentration of temazepam in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0% PERFORMANCE TESTS

DISSOLUTION 〈711〉

Buffer: Dissolve 2 g of sodium hydroxide in 450 mL of water in a 1-L volumetric flask. Adjust with acetic acid to a pH of 4.0, and dilute with water to volume. Deaerate.

Medium: Buffer with 0.05% polysorbate 80; 900 mL

Apparatus 2: 75 rpm

Time: 30 min Detector: UV 310 nm

Standard solution: USP Temazepam RS in Medium

Sample solution: Filter a portion of the solution under test. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Tolerances: NLT 80% (Q ) of the labeled amount of temazepam (C H O N Cl) is dissolved.

UNIFORMITY OF DOSAGE UNITS 〈905〉: Meet the requirements

4 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in well-closed, light-resistant containers.

USP REFERENCE STANDARDS 〈11〉

USP Temazepam RS