Methamphetamine Hydrochloride Tablets

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

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

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1 DEFINITION

Methamphetamine Hydrochloride Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of methamphetamine hydrochloride (C₁₀H₁₅N · HCl).

2 IDENTIFICATION

A. The UV absorption spectrum of the Sample solution, prepared as described in Procedure for content uniformity in Uniformity of Dosage Units, exhibits maxima and minima at the same wavelengths as those of the Standard solution, concomitantly measured.

3 ASSAY

Procedure

Mobile phase: Prepare a degassed solution of 1.1 g of sodium 1-heptanesulfonate in a mixture of water, methanol, and diluted glacial acetic acid (7 in 50) (575:400:25). Adjust with acetic acid to a pH of 3.3 ± 0.1, if necessary. Filter through a 0.5-μm disk.

Standard solution: 0.2 mg/mL of USP Methamphetamine Hydrochloride RS in 0.12 M phosphoric acid. Sonicate if necessary.

Sample solution: Transfer a portion of fine powder from NLT 20 Tablets, nominally equivalent to about 10 mg of methamphetamine hydrochloride, to a 50-mL volumetric flask. Add 20 mL of 0.12 M phosphoric acid, and sonicate for 5 min. Dilute with 0.12 M phosphoric acid to volume, and filter.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 257 nm

Column: 3.9-mm × 30.0-cm; packing L1

Flow rate: 2 mL/min

Injection volume: 20 μL

System suitability

Sample: Standard solution

Suitability requirements

Column efficiency: NLT 1000 theoretical plates

Tailing factor: NMT 1.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of methamphetamine hydrochloride (C₁₀H₁₅N · HCl) in the portion of Tablets taken:

Result = (r_U/r_S) × (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 Methamphetamine Hydrochloride RS in the Standard solution (mg/mL)

C_U = nominal concentration of methamphetamine hydrochloride in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 50 rpm

Time: 45 min

Mobile phase: Acetonitrile and dilute perchloric acid (1 in 20) (300:700). Filter, and degas.

Sample solution: Filter aliquots of the solution in the test, and dilute 2:1 with 0.15 M perchloric acid.

Standard solution: Dissolve USP Methamphetamine Hydrochloride RS in water to obtain a concentration similar to the one expected in the

Sample solution. Dilute 2:1 with 0.15 M perchloric acid.

Chromatographic system

Mode: LC

Detector: UV 211 nm

Column: 3.9-mm × 30-cm; packing L1

Flow rate: 2.5 mL/min

Injection volume: 100 μL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 1.5

Relative standard deviation: NMT 3.0%

Analysis

Samples: Sample solution and Standard solution

Calculate the percentage of the labeled amount of methamphetamine hydrochloride (C₁₀H₁₅N · HCl) dissolved by comparing the major

peak response of the Sample solution with that of the Standard solution.

Tolerances: NLT 75% (Q) of the labeled amount of methamphetamine hydrochloride (C₁₀H₁₅N · HCl) is dissolved.

Change to read:

Uniformity of Dosage Units 〈905〉: Meet the requirements (CN 1-Aug-2023)

Procedure for content uniformity

Solution A: Shake 250 mL of 0.1 N sulfuric acid with 25 mL of chloroform for 10 min. Allow to stand for 1 h with occasional shaking. Drain off the chloroform, and retain the chloroform-saturated sulfuric acid in a stoppered flask.

Standard solution: 0.5 mg/mL of USP Methamphetamine Hydrochloride RS in Solution A

Sample solution: Place 1 Tablet in a 125-mL separator. Add 15 mL of water, and shake by mechanical means for 15 min to dissolve. Add 2.5 mL of 1 N sodium hydroxide, and shake. Extract the liberated methamphetamine with four 10-mL portions of chloroform, collecting the chloroform extracts in a second 125-mL separator. Transfer 10.0 mL of Solution A to the second separator, and shake by mechanical means for 10 min. Allow the layers to separate, and collect the aqueous layer.

Instrumental conditions

Mode: UV

Analytical wavelength: Maximum at about 257 nm

Cell: 1 cm

Blank: Solution A

Analysis

Samples: Standard solution, Sample solution, and Blank

Calculate the percentage of the labeled amount of methamphetamine hydrochloride (C₁₀H₁₅N · HCl) in the portion of Tablets taken:

Result = (A_U/A_S) × (C_S/C_U) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of USP Methamphetamine Hydrochloride RS in the Standard solution (mg/mL)

C_U = nominal concentration of methamphetamine hydrochloride in the Sample solution (mg/mL)

(CN 1-Aug-2023)

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers.

USP Reference Standards 〈11〉

USP Methamphetamine Hydrochloride RS