Cladribine Injection
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).
IDENTIFICATION
• A. Ultraviolet Absorption 
197U
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.
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
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 = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response from the Sample solution |
| rS | = | = peak response from the Standard solution |
| CS | = | = concentration of USP Cladribine RS in the Standard solution (mg/mL) |
| CU | = | = nominal concentration of cladribine in the Sample solution (mg/mL) |
Acceptance criteria:
90.0%–110.0%
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 = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response of each impurity from the Sample solution |
| rS | = | = peak response of cladribine from the Standard solution |
| CS | = | = concentration of USP Cladribine RS in the Standard solution (mg/mL) |
| CU | = | = 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
| Name | Relative Retention Time |
Acceptance Criteria, NMT (%) |
|
|---|---|---|---|
| 2,6-Diaminopurine-2¢-deoxyriboside | 0.41 | 0.2 | |
| 2¢-Deoxyadenosine | 0.47 | 0.2 | |
| 2-Chloroadenine | 0.60 | 0.5 | |
| Cladribine related compound Aa | 0.91 | 0.2 | |
| Cladribine | 1.0 | — | |
| Any individual, unspecified impurity |
— | 0.2 | |
| Total impurities | — | 2.0 | |
|
a
2-Methoxy-2¢-deoxyadenosine.
|
|||
SPECIFIC TESTS
• Bacterial Endotoxins Test 85:
NMT 55 USP Endotoxin Units/mg of cladribine
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.
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
791:
5.5–8.0
• Osmolality and Osmolarity, Osmolality 785:
250–370 mOsmol/kg
785:
250–370 mOsmol/kg
• Particulate Matter in Injections 788:
It meets the requirements for small-volume injections.
788:
It meets the requirements for small-volume injections.
• Other Requirements:
It meets the requirements under Injections 1.
1.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in single-use clear flint glass vials. Store refrigerated at 2
–8C. Protect from light.
–8C. 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
11
USP Cladribine RS 
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USP Cladribine Related Compound A RS
2-Methoxy-2¢-deoxyadenosine.
C11H15N5O4 281.27
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2-Methoxy-2¢-deoxyadenosine.
C11H15N5O4 281.27
USP Endotoxin RS
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Feiwen Mao, M.S.
Senior Scientific Liaison (301) 816-8320 |
(SM32010) Monographs - Small Molecules 3 |
| 85 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison (301) 816-8339 |
(GCM2010) General Chapters - Microbiology |
| 71 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison (301) 816-8339 |
(GCM2010) General Chapters - Microbiology |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP38–NF33 Page 2846
Pharmacopeial Forum: Volume No. 39(2)