Printed on: Wed Feb 08 2023, 11:27:18 PM(EST) Status: Currently Official on 09-Feb-2023 DocId: GUID-0A0860CC-95B7-4A42-BDF5-19DFDEBBC098_4_en-US
Printed by: Dang Van Vu Official Date: Official as of 01-May-2020 Document Type: USP & NF @2023 USPC
Do Not Distribute DOI Ref: d9v7n DOI: https://doi.org/10.31003/USPNF_M750_04_01
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[NOTE—The relative retention times for acetylcysteine
Acetylcysteine and L-phenylalanine are about 0.5 and 1.0,
respectively.]
Suitability requirements
Resolution: NLT 6 between acetylcysteine and
L-phenylalanine
Relative standard deviation: NMT 2.0%
Analysis
C5H9NO3S 163.19 Samples: Standard solution and Sample solution
L-Cysteine, N-acetyl-; Calculate the percentage of acetylcysteine (C5H9NO3S) in
N-Acetyl-L-cysteine CAS RN®: 616-91-1. the portion of Acetylcysteine taken:
DEFINITION
Acetylcysteine contains NLT 98.0% and NMT 102.0% Result = (R U/R S) × (C S/C U) × 100
of C5H9NO3S, calculated on the dried basis.
RU = peak response ratio of acetylcysteine to
IDENTIFICATION L-phenylalanine from the Sample solution
RS = peak response ratio of acetylcysteine to
Change to read: L-phenylalanine from the Standard solution
• A. ▲SPECTROSCOPIC IDENTIFICATION TESTS á197ñ, Infrared CS = concentration of USP Acetylcysteine RS in the
Spectroscopy: 197K▲ (CN 1-May-2020) Standard solution (mg/mL)
CU = concentration of acetylcysteine in the Sample
ASSAY solution (mg/mL)
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• PROCEDURE
Mobile phase: 6.8 g/L of monobasic potassium phosphate. Acceptance criteria: 98.0%–102.0% on the dried basis
Adjust with phosphoric acid to a pH of 3.0. IMPURITIES
Sodium metabisulfite solution: 0.5 mg/mL of sodium • RESIDUE ON IGNITION á281ñ: NMT 0.5%
metabisulfite in water, freshly prepared
Internal standard solution: 5 mg/mL of USP SPECIFIC TESTS
l-Phenylalanine RS in Sodium metabisulfite solution
Standard stock solution: 10 mg/mL of USP Acetylcysteine
RS in Sodium metabisulfite solution
ci • OPTICAL ROTATION, Specific Rotation á781Sñ
Buffer: Mix 29.5 mL of 1 N sodium hydroxide, 50 mL of 1 M
monobasic potassium phosphate, and sufficient water to
Standard solution: 0.5 mg/mL of USP Acetylcysteine RS make 100 mL. Adjust to a pH of 7.0 ± 0.1 by adding more
and 0.25 mg/mL of USP l-Phenylalanine RS in Sodium of either solution, as necessary.
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metabisulfite solution from Standard stock solution and Sample solution: In a 25-mL volumetric flask, mix 1.25 g
Internal standard solution with 1 mL of edetate disodium solution (1 in 100), add
Sample stock solution: 10 mg/mL of Acetylcysteine in 7.5 mL of sodium hydroxide solution (1 in 25), and mix to
Sodium metabisulfite solution dissolve. Dilute with Buffer to volume.
Sample solution: 0.5 mg/mL of Acetylcysteine and Acceptance criteria: +21° to +27°
0.25 mg/mL of USP l-Phenylalanine RS in Sodium • PH á791ñ: 2.0–2.8 in a solution (1 in 100)
O
metabisulfite solution from Sample stock solution and Internal • LOSS ON DRYING á731ñ: Dry a sample at a pressure of about
standard solution 50 mm of mercury at 70° for 4 h: it loses NMT 1.0% of its
Chromatographic system weight.
(See Chromatography á621ñ, System Suitability.)
Mode: LC ADDITIONAL REQUIREMENTS
Detector: UV 214 nm • PACKAGING AND STORAGE: Preserve in tight containers, and
Column: 3.9-mm × 30-cm; packing L1 store at controlled room temperature.
Flow rate: 1.5 mL/min • USP REFERENCE STANDARDS á11ñ
Injection size: 5 µL USP Acetylcysteine RS
System suitability USP l-Phenylalanine RS
Sample: Standard solution
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