Cladribine 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 

Cladribine Injection is a clear, colorless, sterile, preservative-free, isotonic solution. It contains NLT 90.0% and NMT 110.0% of the labeled amount of cladribine (C₁₀H₁₂ClN₅O₃). 

2 IDENTIFICATION 

A. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U 

Sample solution: 0.05 mg/mL of cladribine in water 

Acceptance criteria: Meets the requirements 

B. 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 

Buffer: Dissolve 9.96 g of triethylamine phosphate, accurately weighed, in 500 mL of water, and add another 500 mL of water. Adjust with potassium hydroxide to a pH of 6.1. [Note—Alternatively, dissolve 13.5 mL of triethylamine in 1 L of water, and adjust with phosphoric acid to a pH of 6.1.] 

Mobile phase: Methanol and Buffer (22:78) 

Diluent: Methanol and water (10:90) 

System suitability solution: 0.02 mg/mL each of USP Cladribine RS and USP Cladribine Related Compound A RS in Diluent Standard solution: 0.5 mg/mL of USP Cladribine RS in Diluent 

Sample solution: Nominally, equivalent to 0.5 mg/mL of cladribine in Diluent from Injection 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 265 nm 

Column: 4.6-mm × 15-cm; 5-µm packing L1 

Flow rate: 1 mL/min 

Injection volume: 10 µL 

System suitability 

Samples: System suitability solution and Standard solution 

Suitability requirements 

Resolution: NLT 1.5 between cladribine and cladribine related compound A, System suitability solution 

Tailing factor: NMT 2.0 for the cladribine peak, 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 cladribine (C₁₀H₁₂ClN₅O₃) in the portion of Injection 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 Cladribine RS in the Standard solution (mg/mL) 

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

Acceptance criteria: 90.0%–110.0% 

4 IMPURITIES 

Organic Impurities 

Buffer, Mobile phase, Diluent, System suitability solution, and Sample solution: Proceed as directed in the Assay. Standard solution: 0.01 mg/mL of USP Cladribine RS in Diluent 

Chromatographic system: Proceed as directed in the Assay. In addition, the run time is NLT 2.5 times of the retention time of the cladribine peak for the Sample solution. 

System suitability 

Samples: System suitability solution and Standard solution 

Suitability requirements 

Resolution: NLT 1.5 between cladribine and cladribine related compound A, System suitability solution 

Tailing factor: NMT 2.0 for the cladribine peak, System suitability solution 

Relative standard deviation: NMT 5.0%, Standard solution 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of each impurity in the portion of Injection taken: 

Result = (r_U/r_S) × (C_S/C_U) × 100 

r_U = peak response of each impurity from the Sample solution

r_S = peak response of cladribine from the Standard solution 

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

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

Acceptance criteria: See Table 1. Disregard any impurity peaks less than 0.1%. 

Table 1 

^a 2-Methoxy-2′-deoxyadenosine. 

5 SPECIFIC TESTS 

Bacterial Endotoxins Test 〈85〉: NMT 55 USP Endotoxin Units/mg of cladribine 

Sterility Tests 〈71〉: It meets the requirements when tested as directed for Test for Sterility of the Product to Be Examined, Membrane Filtration. pH 〈791〉: 5.5–8.0 

Change to read: 

Osmolality and Osmolarity 〈785〉 

Osmolality: ( 250–370 mOsmol/kg 

Particulate Matter in Injections 〈788〉: It meets the requirements for small-volume injections. 

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

6 ADDITIONAL REQUIREMENTS 

Packaging and Storage: Preserve in single-use clear int glass vials. Store refrigerated at 2°–8°C. Protect from light. Labeling: Label it to indicate that it is to be diluted with 0.9% Sodium Chloride Injection USP for the single daily dose and to be diluted with bacteriostatic 0.9% Sodium Chloride Injection USP (0.9% benzyl alcohol preserved) to prepare the 7-day infusion solution. USP Reference Standards 〈11〉 

USP Cladribine RS 

USP Cladribine Related Compound A RS 

2-Methoxy-2′-deoxyadenosine. 

C₁₁H₁₅N₅O₄ 281.27