Cimetidine Injection

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 Injection is a sterile solution of Cimetidine Hydrochloride in Water for Injection. It contains NLT 90.0% and NMT 110.0% of the labeled amount of cimetidine (C H N S). 

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: 0.5 mg/mL of USP Cimetidine Hydrochloride RS in a mixture of methanol and water (1:4) Standard solution: 12.5 µg/mL of USP Cimetidine Hydrochloride RS in Mobile phase from Standard stock solution Sample solution: Nominally 10.0 µg/mL of cimetidine, prepared as follows. Transfer an accurately measured volume of Injection, equivalent to about 2 mg of cimetidine, 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 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 

Samples: Standard solution and Sample solution 

Calculate the percentage of the labeled amount of cimetidine (C H N S) in the portion of Injection taken: 

Result = (r_U/r_S) × (C_S/C_U) × (M_r1/M_r2) × 100 

r_U = peak response from the Sample solution 

r_S = peak response from the Standard solution 

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

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

M_r1 = molecular weight of cimetidine, 252.34 

M_r2 = molecular weight of cimetidine hydrochloride, 288.81 

Acceptance criteria: 90.0%–110.0% 

4 SPECIFIC TESTS 

Bacterial Endotoxins Test 〈85〉: NMT 0.5 USP Endotoxin Unit/mg of cimetidine hydrochloride 

pH 〈791〉: 3.8–6.0 

Other Requirements: It meets the requirements in Injections and Implanted Drug Products 〈1〉. 

5 ADDITIONAL REQUIREMENTS 

Packaging and Storage: Preserve in single-dose or multiple-dose glass or plastic containers. Glass containers are preferably of Type I or Type II glass. 

USP Reference Standards 〈11〉 

USP Cimetidine Hydrochloride RS