Ethanesulfonic acid, 2-mercapto-, monosodium salt;
Sodium 2-sulphanylethanesulfonate [19767-45-4].
Mesna contains NLT 96.0% and NMT 102.0% of C2H5NaO3S2, calculated on the dried basis.
• B. Identification TestsGeneral, Sodium 191: A solution meets the requirements of the flame test.
Sample solution: 120 mg of Mesna in 10 mL of water
Analysis: To the Sample solution add 10 mL of 1 M sulfuric acid and 10 mL of 0.1 N iodine VS. Titrate with 0.1 N sodium thiosulfate VS, adding 1 mL of starch TS near the endpoint. Perform a blank determination, and make any necessary correction (see Titrimetry 541). Each mL of sodium thiosulfate is equivalent to 16.42 mg of C2H5NaO3S2.
Acceptance criteria: 96.0%102.0% on the dried basis
• Limit of Chloride
Chloride standard solution: 8.24 µg/mL of sodium chloride in water
Sample solution: 200 mg/mL of Mesna in carbon dioxide-free water
Analysis: To 1 mL of the Sample solution and 15 mL of water add 1 mL of 2 M nitric acid. Add the resulting solution to 1 mL of a silver nitrate solution (17 g in 1000 mL), and allow to stand for 5 min, protected from light. To 10 mL of the Chloride standard solution add 5 mL of water and 1 mL of 2 M nitric acid. To this solution add 1 mL of silver nitrate solution (17 g in 1000 mL) and allow to stand for 5 min, protected from light. When viewed against a dark background, the Sample solution is not more turbid than the Chloride standard solution.
Acceptance criteria: NMT 250 ppm
• Limit of Sulfate
Sulfate standard solution: 1.81 mg/mL of potassium sulfate in alcohol. Immediately before use, dilute with alcohol to 100 times its volume, and mix.
Sample solution: Add 5.0 mL of the Sample solution prepared as directed in the test for Limit of Chloride to a 30-mL volumetric flask, and dilute with water to volume.
Analysis: Add 3 mL of a 250-g/L solution of barium chloride to 4.5 mL of Sulfate standard solution. Shake and allow to stand for 1 min. To 2.5 mL of this solution add 15 mL of the Sample solution and 0.5 mL of acetic acid. Use 15 mL of this mixture for comparison with 15 mL of the Sulfate standard solution, prepared in the same manner, but using the Sulfate standard solution instead of the Sample solution. After 5 min, any opalescence in the Sample solution is not more intense than that in the Sulfate standard solution.
Acceptance criteria: NMT 300 ppm
• Heavy Metals, Method I 231: 10 ppm
Mobile phase: In a 1000-mL volumetric flask dissolve 2.94 g of potassium dihydrogen phosphate, 2.94 g of dipotassium hydrogen phosphate, and 2.6 g of tetrabutylammonium hydrogen sulfate in about 600 mL of water. Adjust to a pH of 2.3 with phosphoric acid, add 335 mL of methanol, and dilute with water to volume.
System suitability solution: 0.18 mg/mL and 0.004 mg/mL of USP Mesna RS and USP Mesna Related Compound A RS, respectively, in Mobile phase
Standard solution 1: 8 µg/mL and 120 µg/mL of USP Mesna Related Compound A RS and USP Mesna Related Compound B RS, respectively, in Mobile phase
Standard solution 2: 12 µg/mL of USP Mesna RS in Mobile phase
Sample solution: 4 mg/mL of Mesna in Mobile phase
Detector: UV 235 nm
Column: 4.6-mm × 25-cm; 10-µm packing L1
Flow rate: 1 mL/min
Run time: Four times the elution time for mesna
Injection size: 20 µL
Sample: System suitability solution
[NoteThe relative retention times for mesna and mesna related compound A are about 1.0 and 1.4, respectively. ]
Resolution: NLT 3.0 between mesna and mesna related compound A
Samples: Standard solution 1, Standard solution 2, and Sample solution
[NoteIdentify the peaks using the relative retention times provided in Impurity Table 1. ]
Calculate the percentage of mesna related compound A in the portion of Mesna taken:
Result = (rU/rS) × (CS/CU) × 100
Calculate the percentage of mesna related compound B in the portion of Mesna taken:
Result = (rU/rS) × (CS/CU) × 100
Calculate the percentage of any specified impurities (2-(carbamimidoylsulphanyl)ethanesulfonic acid;2-[[(guanidino)(imino)methyl]sulphanyl]ethanesulfonic acid; 2-(4,6-diamino-1,3,5-triazin-2-yl)sulphanylethanesulfonic acid) and any unspecified impurities in the portion of Mesna taken:
Result = (rU/rS) × (CS/CU) × F × 100
Individual impurities: See Impurity Table 1.
Impurity Table 1
• Loss on Drying: Dry 1 g in a vacuum at a pressure not exceeding 1 mm of mercury at 60 over phosphorus pentoxide for 2 h: it loses NMT 1.0% of its weight.
• pH 791: 4.56.0
• Packaging and Storage: Preserve in a tight container, and store at room temperature.
• USP Reference Standards 11
USP Mesna Related Compound A RS
USP Mesna Related Compound B RS
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USP35NF30 Page 3820Pharmacopeial Forum: Volume No. 34(5) Page 1168