Cimetidine 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 

Cimetidine Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of cimetidine (C₁₀H₁₆N₆S). 

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. 

3 ASSAY 

Procedure 

Mobile phase: Transfer 200 mL of methanol and 0.3 mL of phosphoric acid to a 1000-mL volumetric flask, dilute with water to volume, and filter. 

Standard stock solution: 0.4 mg/mL of USP Cimetidine RS in methanol and water (1:4), prepared by initially dissolving the USP Cimetidine RS in methanol using 20% of the nal volume and diluting that solution with water to volume 

Standard solution: 0.01 mg/mL of USP Cimetidine RS in Mobile phase from the Standard stock solution 

Sample stock solution: Weigh, and finely powder NLT 20 Tablets. Transfer a portion of the powder, equivalent to about 100 mg of cimetidine, to a 250-mL volumetric flask. Add 50 mL of methanol, shake for 2 min, add 40 mL of water, sonicate for 15 min, and dilute with water to volume. 

Sample solution: Transfer 5.0 mL of the Sample stock solution to a 200-mL volumetric flask, and dilute with Mobile phase to volume. Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 220 nm 

Column: 3.9-mm × 30-cm; packing L1 

Flow rate: 2.0 mL/min 

Injection volume: 50 µL 

System suitability 

Sample: Standard solution 

Suitability requirements 

Capacity factor, k′: NLT 0.6 

Column efficiency: NLT 1000 theoretical plates 

Relative standard deviation: NMT 2.0% 

Analysis: Calculate the percentage of the labeled amount of cimetidine (C₁₀H₁₆N₆S) in the portion of Tablets taken:   

Result = (r_U/r_S) × (C_S/C_U)  × 100 

r_U = peak response from the Sample solution 

r_S = peak response from the Standard solution 

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

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

Acceptance criteria: 90.0%–110.0% 

4 PERFORMANCE TESTS 

Dissolution 〈711〉 

Medium: 0.01 N hydrochloric acid; 900 mL 

Apparatus 1: 100 rpm. A 20-mesh basket may be used for 800-mg strength Tablets. 

Time: 15 min 

Standard solution: USP Cimetidine RS in Medium 

Sample solution: Filtered solution under test, diluted with Medium to a concentration that is similar to that of the Standard solution Detector: UV, the wavelength of maximum absorbance at about 218 nm 

Tolerances: NLT 80% (Q) of the labeled amount of cimetidine (C H N S) is dissolved. 

Uniformity of Dosage Units 〈905〉: Meet the requirements 

5 ADDITIONAL REQUIREMENTS 

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

USP Reference Standards 〈11〉 

USP Cimetidine RS