Dacarbazine for 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

Dacarbazine for Injection is a sterile, freeze-dried mixture of dacarbazine and suitable buffers or diluents. It contains NLT 90.0% and NMT 110.0% of the labeled amount of dacarbazine (C₆H₁₀N₆O) [CAUTION-Great care should be taken to prevent inhaling particles of Dacarbazine for Injection and exposing the skin to it.]

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.

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

3.1 PROCEDURE

Protect solutions containing dacarbazine from light and store at 2º - 8º

Solution A: 4.1 g/L of sodium acetate in water. Adjust with phosphoric acid to a pH of 7.0.

Solution B: 4.1 g/L of sodium acetate in water. Adjust with phosphoric acid to a pH of 5.5. Mix this solution with acetonitrile (75:25).

Mobile phase: See Table 1. Return to original conditions, and equilibrate the system for 10 min.

Table 1

Diluent: 0.1 mg/mL of citric acid in water

Standard solution: 0.1 mg/mL of USP Dacarbazine RS in Diluent

Sample solution: Nominally equivalent to 0.1 mg/mL of dacarbazine in water, from Dacarbazine for Injection

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 250 nm. For Identification B, use a diode array detector in the range of 200-400 nm.

Column: 4.6-mm x 25-cm; 5-µm packing 11

Autosampler temperature: 2°-8°

Flow rate: 1.0 mL/min

Injection volume: 20 µL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 1.5

Relative standard deviation: NMT 1.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of dacarbazine (C₆H₁₀N₆O) in the portion of Dacarbazine for Injection taken:

Result = (r_u/r_s) x (C_s/C_u) × 100

r_u = peak response from the Sample solution

r_s = peak response from the Standard solution S

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

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

Acceptance criteria: 90.0%-110.0%

3.2 UNIFORMITY OF DOSAGE UNITS (905): Meets the requirements

4 IMPURITIES

Change to read:

4.1 ORGANIC IMPURITIES

Protect solutions containing dacarbazine and its related compounds from light and store at 2°-8°.

Solution A, Solution B, Mobile phase, and Chromatographic system: Proceed as directed in the Assay.

Standard solution: 8.0 µg/mL of USP Dacarbazine RS in water, from the Standard solution in the Assay

Dacarbazine related compound A standard solution: 0.04 mg/mL of USP Dacarbazine Related Compound A RS in water. Sonicate to ensure complete dissolution.

Dacarbazine related compound B standard solution: 0.04 mg/mL of USP Dacarbazine Related Compound B RS in water. Sonicate to ensure complete dissolution.

Sensitivity solution: 2.0 µg/mL of USP Dacarbazine RS in water from Standard solution

Sample solution: Nominally equivalent to 4.0 mg/mL of dacarbazine in water prepared as follows. Transfer the contents of 1 vial into a suitable volumetric flask, rinse the vial with several portions of water, add the rinsings into the same volumetric flask and dilute with water to volume.

System suitability

Samples: Dacarbazine related compound A standard solution, Dacarbazine related compound B standard solution, and Sensitivity solution

Suitability requirements

Relative standard deviation 1: NMT 5.0%, Dacarbazine related compound A standard solution

Relative standard deviation 2: NMT 5.0%, Dacarbazine related compound B standard solution

Signal-to-noise ratio: NLT (ERR 1-Sep-2022) 10, Sensitivity solution

Analysis

Samples: Standard solution, Dacarbazine related compound A standard solution, Dacarbazine related compound B standard solution, and Sample solution

Calculate the percentage of 5-aminoimidazole-4-carboxamide (free base of USP Dacarbazine Related Compound A RS) in the portion of Dacarbazine for Injection taken:

Result = (r_u/r_s) x (C_s/C_u)  x (M_r1/M_r2) x 100

r_u = peak response of 5-aminoimidazole-4-carboxamide from the Sample solution

r_s = peak response of dacarbazine related compound A from the Dacarbazine related compound A standard solution 

C_s = concentration of USP Dacarbazine Related Compound A RS in the Dacarbazine related compound A standard solution (mg/mL) 

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

M_r1 = molecular weight of 5-aminoimidazole-4-carboxamide, 126.12

M_r2 = molecular weight of USP Dacarbazine Related Compound A RS, 162.58

Calculate the percentage of 2-azahypoxanthine (anhydrous) (anhydrous form of USP Dacarbazine Related Compound B RS) in the portion of Dacarbazine for Injection taken:

Result = (r_u/r_s) x (C_s/C_u) × 100

r_u = peak response of 2-azahypoxanthine (anhydrous) from the Sample solution Tu

r_s = peak response of dacarbazine related compound B from the Dacarbazine related compound B standard solution S

C_s = concentration of USP Dacarbazine Related Compound B RS in the Dacarbazine related compound B standard solution (mg/mL)

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

Calculate the percentage of each individual unspecified impurity in the portion of Dacarbazine for Injection taken:

Result = (r_u/r_s) x (C_s/C_u) × 100

r_u = peak response of each unspecified impurity from the Sample solution

r_s = peak response of dacarbazine from the Standard solution 

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

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

Acceptance criteria: See Table 2. The reporting threshold is 0.05%.

Table 2

a It is the free base of USP Dacarbazine Related Compound A RS (C₄H₆N₄O).

b It is the anhydrous form of USP Dacarbazine Related Compound B RS (C₄H₃N₅O).

5 SPECIFIC TESTS

PH (791)

Sample solution: Nominally equivalent to 10 mg/mL of dacarbazine in water, from Dacarbazine for Injection

Acceptance criteria: 3.0-4.0

WATER DETERMINATION (921), Method I: NMT 1.5%

BACTERIAL ENDOTOXINS TEST (85): It contains NMT 0.52 USP Endotoxin Units/mg of dacarbazine.

STERILITY TESTS (71): Meets the requirements

COMPLETENESS OF SOLUTION: When dissolved as directed in the labeling, it yields a clear, pale yellow to yellow solution.

CONSTITUTED SOLUTION: At the time of use, it meets the requirements in Injections and Implanted Drug Products (1), Product Quality Tests Common to Parenteral Dosage Forms, Specific Tests, Completeness and clarity of solutions.

PARTICULATE MATTER IN INJECTIONS (788): Meets the requirements for small-volume injections

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in single-dose or multiple-dose containers as described in Packaging and Storage Requirements (659), Injection Packaging, Packaging for Constitution, preferably of Type I glass, protected from light.

LABELING: Meets the requirements in Labeling (7), Labels and Labeling for Injectable Products

USP REFERENCE STANDARDS (11)

USP Dacarbazine RS

USP Dacarbazine Related Compound A RS

5-Aminoimidazole-4-carboxamide hydrochloride.

C₄H₆N₄O . HCI  162.58

USP Dacarbazine Related Compound B RS

2-Azahypoxanthine monohydrate.

C₄H₃N₅O . H₂O      155.12