Demeclocycline Hydrochloride Tablets

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

Demeclocycline Hydrochloride Tablets contain NLT 90.0% and NMT 125.0% of the labeled amount of demeclocycline hydrochloride (C₂₁H₂₁ClN₂O₈ · HCl).

2 IDENTIFICATION

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

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B. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

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3.1 Procedure

Solution A: Mix appropriate volumes of 0.2 M dibasic potassium phosphate and 0.2 M monobasic potassium phosphate to prepare a buffer with a pH of 9.0.

Solution B: 0.02 M tetrabutylammonium hydrogen sulfate. Adjust with sodium hydroxide TS to a pH of 9.0.

Solution C: 0.01 M edetate disodium. Adjust with sodium hydroxide TS to a pH of 9.0.

Mobile phase: Transfer 80 g of tertiary butyl alcohol to a 1000-mL volumetric flask with the aid of 200 mL of water. Add 100 mL of Solution A, 150 mL of Solution B, and 100 mL of Solution C. Dilute with water to volume, and degas.

Diluent: 0.01 N hydrochloric acid

System suitability solution: 1 mg/mL of USP Demeclocycline Hydrochloride RS in Diluent. Allow to stand for 3 h.

Standard solution: 1 mg/mL of USP Demeclocycline Hydrochloride RS in Diluent

Sample solution: Nominally 1 mg/mL of demeclocycline hydrochloride prepared as follows. Weigh and finely powder NLT 10 Tablets. Transfer a portion, containing nominally 50 mg of demeclocycline hydrochloride, to a 50-mL volumetric flask, and dilute with Diluent to volume. Sonicate for 5 min, and centrifuge for 5 min. Pass a portion of the supernatant through a suitable filter of 1.5-µm or finer pore size.

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 254 nm. For Identification B, use a diode array detector in the range of 200–400 nm.
• Column: 4.6-mm × 25-cm; 8-µm packing L21
• Column temperature: 60 ± 0.5°
• Flow rate: 1 mL/min
• Injection volume: 20 µL

System suitability

• Samples: System suitability solution and Standard solution
• [Note-The relative retention times for epidemethylchlortetracycline and demeclocycline are about 0.7 and 1.0, respectively.]
• Suitability requirements
• Resolution: NLT 3.0 between the epidemethylchlortetracycline and demeclocycline peaks, System suitability solution
• Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of demeclocycline hydrochloride (C₂₁H₂₁ClN₂O₈ · HCl) in the portion of Tablets taken:

Result = (r_u/r_s) × (C_s/C_u) × P × F × 100

r_u = peak response from the Sample solution

r_s = peak response from the Standard solution

C_s = concentration of USP Demeclocycline Hydrochloride RS in the Standard solution (mg/mL)

C_u = nominal concentration of demeclocycline hydrochloride in the Sample solution (mg/mL)

P = potency of demeclocycline in USP Demeclocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Acceptance criteria: 90.0%–125.0%

4 PERFORMANCE TESTS

4.1 Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 75 rpm

Time: 45 min

Standard solution: Prepare a solution with a known concentration of USP Demeclocycline Hydrochloride RS in Medium.

Sample solution: Sample per Dissolution 〈711〉. A filtered portion of the solution under test suitably diluted with Medium

Instrumental conditions

• (See Ultraviolet-Visible Spectroscopy 〈857〉.)
• Mode: UV
• Analytical wavelength: 274 nm

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of demeclocycline (C₂₁H₂₁ClN₂O₈) dissolved:

Result = (A_U/A_S)× (C_s/L) × D × V × P × F × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_s = concentration of USP Demeclocycline Hydrochloride RS in the Standard solution (mg/mL)

L = label claim (mg/Tablet)

D = dilution factor of the Sample solution

V = volume of Medium, 900 mL

P = potency of demeclocycline in USP Demeclocycline Hydrochloride RS (µg/mg)

F = conversion factor, 0.001 mg/µg

Tolerances: NLT 75% (Q) of the labeled amount of demeclocycline (C₂₁H₂₁ClN₂O₈) is dissolved.

4.2 Uniformity of Dosage Units 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

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Packaging and Storage: Preserve in tight, light-resistant containers. Store at controlled room temperature.

USP Reference Standards 〈11〉

USP Demeclocycline Hydrochloride RS