Amodiaquine

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

C₂₀H₂₂ClN₃O 355.86

Phenol, 4-[(7-chloro-4-quinolinyl)amino]-2-[(diethylamino)-methyl]-;

4-[(7-Chloro-4-quinolyl)amino]-α-(diethylamino)-o-cresol CAS RN^®: 86-42-0; UNII: 220236ED28.

1 DEFINITION

Amodiaquine contains NLT 97.0% and NMT 103.0% of amodiaquine (C₂₀H₂₂ClN₃O), calculated on the anhydrous basis.

2 IDENTIFICATION

Change to read:

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

Standard: Dissolve 20 mg of USP Amodiaquine Hydrochloride RS in 10 mL of water in a separator, add 1 mL of ammonium hydroxide, and extract by shaking with 25 mL of chloroform. Draw off and evaporate the chloroform extract, and dry the residue at 105° for 2 h.

Acceptance criteria: Meets the requirements

Change to read:

B. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U (CN 1-May-2020)

Sample solution: 10 µg/mL in 0.1 N hydrochloric acid

Acceptance criteria: Meets the requirements

3 ASSAY

Procedure

Standard solution: 15 µg/mL of USP Amodiaquine Hydrochloride RS in 0.1 N hydrochloric acid

Sample solution: 15 µg/mL of Amodiaquine in 0.1 N hydrochloric acid

3.1 Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV

Analytical wavelength: 342 nm

Cell: 1 cm

Blank: 0.1 N hydrochloric acid

4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of amodiaquine (C₂₀H₂₂ClN₃O) in the portion of Amodiaquine taken:

Result = (A_U /A_S ) × (C_S /C_U ) × (M_r1 /M_r2 ) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of USP Amodiaquine Hydrochloride RS in the Standard solution (µg/mL)

C_U = concentration of Amodiaquine in the Sample solution (µg/mL)

M_r1 = molecular weight of amodiaquine, 355.86

M_r2 = molecular weight of anhydrous aminodiaquine hydrochloride, 428.79

Acceptance criteria: 97.0%–103.0% on the anhydrous basis

5 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.2%

Organic Impurities

Standard solution A: To 20 mg of USP Amodiaquine Hydrochloride RS in a glass-stoppered test tube add 1.0 mL of chloroform (saturated with ammonium hydroxide), and shake vigorously for 2 min. Allow the solids to settle, and decant the liquid into a second test tube.

Standard solution B: Standard solution A and chloroform (saturated with ammonium hydroxide) (1 in 200)

Sample solution: 15 mg/mL of Amodiaquine in chloroform (saturated with ammonium hydroxide)

5.1 Chromatographic system

(See Chromatography 〈621〉, Thin-Layer Chromatography.)

Mode: TLC

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture

Application volume: 10 µL

Developing solvent system: Chloroform (saturated with ammonium hydroxide) and dehydrated alcohol (9:1)

5.2 Analysis

Samples: Standard solution A, Standard solution B, and Sample solution

Develop the chromatogram until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, allow the solvent to evaporate, and examine the plate under short-wavelength UV light.

Acceptance criteria: The chromatograms show principal spots at about the same R value; and no secondary spot, if present in the F chromatogram from the Sample solution, is more intense than the principal spot obtained from Standard solution B.

6 SPECIFIC TESTS

Water Determination, Method I〈921〉: NMT 0.5%

7 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

USP Reference Standards 〈11〉

USP Amodiaquine Hydrochloride RS