Dextroamphetamine Sulfate

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION 

Dextroamphetamine Sulfate, the dextrorotatory isomer of Amphetamine sulfate, contains NLT 98.0% and NMT 102.0% of dextroamphetamine sulfate [(C₉H₁₃N)₂ . H₂SO₄], calculated on the dried basis. 

2 IDENTIFICATION 

Change to read: 

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197M (CN 1-May-2020) 

B. The retention time 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 

Solution A: Add 5.0 mL of triuoroacetic acid to 900 mL of water, adjust with ammonium hydroxide to a pH of 2.2 ± 0.1, and add 100 mL of acetonitrile. 

Solution B: Acetonitrile 

Mobile phase: See Table 1. 

Table 1 

Standard solution: 2.0 mg/mL of USP Dextroamphetamine Sulfate RS in Solution A 

System suitability solution: Transfer about 40 mL of the Standard solution to a 50-mL volumetric ask. Using a microliter syringe, add 1 µL each of USP Dextroamphetamine Related Compound A RS and USP Dextroamphetamine Related Compound B RS. Dilute with Standard solution to volume. 

Sample solution: 2.0 mg/mL of Dextroamphetamine Sulfate in Solution A 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 257 nm 

Column: 4.6-mm × 15-cm; 5-µm packing L1 

Column temperature: 40° 

Flow rate: 1.5 mL/min 

Injection volume: 20 µL 

System suitability 

Samples: Standard solution and System suitability solution 

[Note—See Table 2 for the relative retention times.] 

Suitability requirements 

Resolution: NLT 3.0 between dextroamphetamine related compound A and dextroamphetamine related compound B, System suitability solution 

Tailing factor: NMT 3.0 for dextroamphetamine, System suitability solution 

Relative standard deviation: NMT 2.0%, Standard solution 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of dextroamphetamine sulfate [C₉H₁₃N)₂ . H₂SO₄] in the portion of Dextroamphetamine Sulfate 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 

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

C_u = concentration of Dextroamphetamine Sulfate in the Sample solution (mg/mL) 

Acceptance criteria 98.0%–102.0% on the dried basis 

4 IMPURITIES 

4.1 Residue on Ignition 〈281〉: NMT 0.1% 

4.2 Organic Impurities 

Solution A, Solution B, Mobile phase, Standard solution, System suitability solution, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay. 

Analysis 

Samples: Standard solution and Sample solution 

Calculate the percentage of each impurity in the portion of Dextroamphetamine Sulfate taken: 

Result = (r_u/r_s) x (C_s/C_u) × (1/F) × 100 

r_u = peak response of each impurity from the Sample solution  

r_s = peak response of dextroamphetamine from the Standard solution 

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

C_u = concentration of Dextroamphetamine Sulfate in the Sample solution (mg/mL) 

F = relative response factor (see Table 2) 

Acceptance criteria: See Table 2. 

Table 2 

5 SPECIFIC TESTS 

5.1 Optical Rotation, Specific Rotation〈781S〉 

Sample solution: 40 mg/mL of Dextroamphetamine Sulfate in water 

Acceptance criteria: +20° to +23.5° 

5.2 pH 〈791〉 

Sample solution: 50 mg/mL of Dextroamphetamine Sulfate in water 

Acceptance criteria: 5.0–6.0 

5.3 Loss on Drying 〈731〉 

Analysis: Dry at 105° for 2 h. 

Acceptance criteria: NMT 1.0% 

6 ADDITIONAL REQUIREMENTS 

Packaging and Storage: Preserve in well-closed containers. 

USP Reference Standards 〈11〉 

USP Dextroamphetamine Related Compound A RS 

1-Phenyl-2-propanol. 

C₉H₁₂O           136.19 

USP Dextroamphetamine Related Compound B RS 

Phenyl acetone. 

C₉H₁₀O           134.18 

USP Dextroamphetamine Sulfate RS