Arginine Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of arginine or arginine hydrochloride in an amount equivalent to arginine (C6H14N4O2).
• A. Thin-Layer Chromatographic Identification Test 201
Standard solution: 1.5 mg/mL of USP l-Arginine RS or USP Arginine Hydrochloride RS in water
Sample solution: Weigh the content of NLT 20 Capsules, mix, and transfer a portion of the content, equivalent to about 150 mg of arginine, to a 100-mL volumetric flask, add 80 mL of water, sonicate for 15 min, dilute with water to volume, mix, and filter.
Application volume: 5 µL
Developing solvent system: Isopropyl alcohol and ammonium hydroxide (7:3)
Spray reagent: 2 mg/mL of ninhydrin in a mixture of butyl alcohol and 2 N acetic acid (95:5)
Analysis: Proceed as directed for Chromatography 621, Thin-Layer Chromatography. Dry the plate at 100105 until the ammonia disappears completely. Spray with the Spray reagent, and heat at 100105 for about 15 min. Examine the plate under white light.
Acceptance criteria: The principal spot from the Sample solution corresponds in appearance and RF value to that of the Standard solution.
• B. The retention time of the major peak of the Sample solution corresponds to that from the Standard solution, as obtained in the Strength.
Buffer: 6.9 mg/mL of monobasic sodium phosphate in water. Adjust with phosphoric acid to a pH of 3.5.
Solution A: 0.5 mg/mL of 1-octanesulfonic acid sodium salt in Buffer
Mobile phase: Solution A and acetonitrile (95:5)
Standard solution: 1.5 mg/mL of USP l-Arginine RS or USP Arginine Hydrochloride RS in Buffer
Sample solution: Weigh the content of NLT 20 Capsules, mix, and transfer a portion of the content, equivalent to about 150 mg of arginine, to a 100-mL volumetric flask, add 80 mL of Buffer, sonicate for 15 min, dilute with Buffer to volume, mix, and filter.
Detector: UV 215 nm
Column: 4.6-mm × 25-cm; packing L7
Flow rate: 0.8 mL/min
Injection size: 10 µL
Sample: Standard solution
Column efficiency: NLT 1500 theoretical plates
Relative standard deviation: NMT 2.0% from the arginine peak, in repeated injections
Samples: Standard solution and Sample solution
Calculate the percentage of the labeled amount of arginine in the portion of Capsules taken:
Result = (rU/rS) × (CS/CU) × 100
Acceptance criteria: 90.0%110.0% of the labeled amount of arginine (C6H14N4O2)
• Disintegration and Dissolution of Dietary Supplements 2040: Meet the requirements for Dissolution
Medium: 0.1 N hydrochloric acid; 900 mL
Apparatus 2: 100 rpm
Time: 60 min
Standard solution: Proceed as directed in the Procedure for Strength.
Sample solution: Sample per Disintegration and Dissolution of Dietary Supplements 2040. Dilute with Medium to a concentration similar to that of the Standard solution.
Analysis: Determine the amount of arginine dissolved in the Procedure for Strength, making any necessary modifications.
Tolerances: NLT 75% of the labeled amount of arginine (C6H14N4O2) is dissolved.
• Weight Variation of Dietary Supplements 2091: Meet the requirements
• Packaging and Storage: Preserve in tight, light-resistant containers.
• Labeling: The label states the form of arginine that is used and the equivalent amount of arginine.
• USP Reference Standards 11
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 1192Pharmacopeial Forum: Volume No. 36(1) Page 147