Neotame
C20H30N2O5 378.46
l-Phenylalanine, N-[N-(3,3-dimethylbutyl)-l-
-aspartyl]-1-methyl ester;
N-[N-(3,3-Dimethylbutyl)-l--aspartyl]-l-phenylalanine 1-methyl ester
[165450-17-9].
(nee' oh tame).
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C20H30N2O5 378.46
l-Phenylalanine, N-[N-(3,3-dimethylbutyl)-l-
-aspartyl]-1-methyl ester;
N-[N-(3,3-Dimethylbutyl)-l-
-aspartyl]-l-phenylalanine 1-methyl ester
[165450-17-9].DEFINITION
Neotame contains NLT 97.0% and NMT 102.0% of neotame (C20H30N2O5), calculated on the anhydrous basis.
IDENTIFICATION
ASSAY
• Procedure
Mobile phase:
Dissolve 3.0 g of sodium 1-heptanesulfonate in 740 mL of water in a suitable 1000-mL vessel, and add 3.8 mL of triethylamine. Adjust the resulting solution with phosphoric acid to a pH of 3.5, and dilute with water to 750 mL. Add 250 mL of acetonitrile, and adjust with phosphoric acid to an apparent pH of 3.7.
Standard solution:
1.0 mg/mL of USP Neotame RS in Mobile phase
Sample solution:
1.0 mg/mL of Neotame in Mobile phase.
[Note—This solution is stable for up to 32 h when stored at a temperature of 0
–10. ]
–10. ]
Chromatographic system
Mode:
LC
Detector:
UV 210 nm
Column:
4.6-mm × 10-cm; packing L1
Column temperature:
45
Flow rate:
1.5 mL/min
Injection size:
25 µL
System suitability
Sample:
Standard solution
Suitability requirements
Tailing factor:
NMT 2.0
Relative standard deviation:
NMT 2.0%
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of neotame (C20H30N2O5) in the portion of Neotame 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 Neotame RS in the Standard solution (mg/mL) |
| CU | = | = concentration of Neotame in the Sample solution (mg/mL) |
Acceptance criteria:
97.0%–102.0% on the anhydrous basis
IMPURITIES
• Residue on Ignition 
281
:
NMT 0.2%
281:
NMT 0.2%
• Lead 251
251
[Note—Use acid-cleaned (mixture of 5% nitric acid and 5% hydrochloric acid followed by rinsing with water) autosampler cups and volumetric glassware to avoid contamination. For the preparation of all aqueous solutions and for the rinsing of glassware before use, use water that has been passed through a strong-acid, strong-base, mixed-bed ion-exchange resin. Select all reagents to have as low a content of lead as practicable. Store standards and samples in acid-cleaned polyethylene containers. ]
Diluent:
Transfer 2 mL of lead-free nitric acid into a 1000-mL volumetric flask, dilute with water to volume, and mix.
Standard stock solution:
79.9 mg of lead nitrate in 100 mL of Diluent in a 500-mL volumetric flask, and dilute with Diluent to volume. Transfer 10.0 mL of the resulting solution into a 100-mL volumetric flask, and dilute with Diluent to volume. Each mL of the Standard stock solution contains the equivalent of 10 µg of lead.
Standard solution A:
Dilute an aliquot of the Standard stock solution with Diluent to obtain a solution having a concentration of 0.03 µg/mL.
Standard solution B:
Dilute an aliquot of the Standard stock solution with Diluent to obtain a solution having a concentration of 0.015 µg/mL.
Sample solution:
Transfer 160 mg of Neotame to a 10-mL volumetric flask. Dissolve in and dilute with Diluent to volume.
Blank:
Diluent
Instrumental conditions
Mode:
Atomic absorption spectrophotometer with a graphite furnace, pyrolytically coated graphite tubes, a solid pyrolytic graphite platform, and a background compensation system
Analytical wavelength:
283.3 nm
Lamp:
Lead hollow-cathode
Purge gas:
Argon
Alternate gas:
Breathing-quality air
Volume:
15 µL. [Note—Optimize the instrument program as recommended by the manufacturer for lead, using a char temperature of 500 and an atomization temperature of 2000. ]
and an atomization temperature of 2000. ]
Analysis
Samples:
Standard solution A, Standard solution B, Sample solution, and Blank
Correct the area responses of the Sample solution, Standard solution A, and Standard solution B for the Blank area response. Generate the appropriate lead calibration algorithm, and determine the lead concentration in the Sample solution, in µg/mL.
Calculate the ppm of lead in the portion of Neotame taken:
Result = (C/W) × V × F
| C | = | = blank-corrected lead concentration in the Sample solution (µg/mL) |
| W | = | = weight of Neotame taken to prepare the Sample solution (mg) |
| V | = | = volume of the Sample solution, 10 mL |
| F | = | = conversion of mg to g |
Acceptance criteria:
NMT 2 ppm
• Related Compounds
Mobile phase and Chromatographic system:
Proceed as directed in the Assay.
Standard solution A:
0.03 mg/mL of USP Neotame Related Compound A RS in Mobile phase
Standard solution B:
Prepare as directed for the Standard solution in the Assay.
Detector sensitivity solution:
Transfer 2 mL of Standard solution A to a 50-mL volumetric flask, and dilute with Mobile phase to volume.
Sample solution:
2 mg/mL of Neotame in Mobile phase.
[Note—This solution is stable for up to 32 h when stored at a temperature of 0 to 10. ]
to 10. ]
System suitability
Samples:
Standard solution A and Detector sensitivity solution
Suitability requirements
Signal-to-noise ratio:
NLT 10, Detector sensitivity solution
Relative standard deviation:
NMT 5.0%, Standard solution A
Analysis
Samples:
Standard solution A, Standard solution B, and Sample solution
Calculate the percentage of neotame related compound A in the portion of Neotame taken:
Result = (rU/rS) × (CS/CU) × 100
| rU | = | = neotame related compound A peak response from the Sample solution |
| rS | = | = neotame related compound A peak response from Standard solution A |
| CS | = | = concentration of USP Neotame Related Compound A RS in Standard solution A (mg/mL) |
| CU | = | = concentration of Neotame in the Sample solution (mg/mL) |
Acceptance criteria:
NMT 1.5%
Calculate the percentage of other impurities in the portion of Neotame taken:
Result = (rT/rS) × (CS/CU) × 100
| rT | = | = sum of the responses of all impurity peaks (except that of neotame related compound A and the solvent peak, if observed) in the Sample solution |
| rS | = | = response of the neotame peak in Standard solution B |
| CS | = | = concentration of USP Neotame RS in Standard solution B (mg/mL) |
| CU | = | = concentration of Neotame in the Sample solution (mg/mL) |
Acceptance criteria:
NMT 2.0%
SPECIFIC TESTS
40.0
• Water Determination, Method Ic 921:
NMT 5.0%
921:
NMT 5.0%
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers, store in a dry place, and avoid exposure to excessive heat.
• USP Reference Standards 11
11
USP Neotame RS
USP Neotame Related Compound A RS
N-[3,3-Dimethylbutyl)-l--aspartyl]-l-phenylalanine.
N-[3,3-Dimethylbutyl)-l-
-aspartyl]-l-phenylalanine.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 1874
Pharmacopeial Forum: Volume No. 31(2) Page 497