Thiamine Hydrochloride

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

Thiamine Hydrochloride contains NLT 98.0% and NMT 102.0% of thiamine hydrochloride, calculated on the anhydrous basis.

2 IDENTIFICATION

Change to read:

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

Analysis: Dry specimens at 105° for 2 h.

Acceptance criteria: Meets the requirements

B. Identification Tests—General, Chloride〈191〉: A 20-mg/mL solution meets the requirements.

3 ASSAY

Procedure

Solution A: 0.005 M sodium 1-octanesulfonate in dilute glacial acetic acid (1 in 100)

Solution B: Methanol and acetonitrile (3:2)

Mobile phase: Solution B and Solution A (40:60)

Internal standard solution: 2% (v/v) of methylbenzoate in methanol

Standard solution: Prepare a 1-mg/mL solution of USP Thiamine Hydrochloride RS in Mobile phase. Transfer 20.0 mL of this solution and 5.0mL of Internal standard solution to a 50-mL volumetric flask, and dilute with Mobile phase to volume. The Standard solution contains 400μg/mL of thiamine hydrochloride.

Sample solution: Prepare a 2-mg/mL of Thiamine Hydrochloride in Mobile phase. Transfer 10.0 mL of this solution and 5.0 mL of Internal standard solution to a 50-mL volumetric flask, and dilute with Mobile phase to volume.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4-mm × 30-cm; packing L1

Flow rate: 1 mL/min

[Note—The flow rate may be adjusted as needed to obtain a retention time of about 12 min for thiamine hydrochloride.]

Injection size: 10 μL

System suitability

Sample: Standard solution

Suitability requirements

Resolution: NLT 4.0 between the thiamine and methylbenzoate peaks

Tailing factor: NMT 2.0 for the thiamine peak

Column efficiency: NLT 1500 theoretical plates for the thiamine peak

Relative standard deviation: NMT 2.0% for the ratios of thiamine peak areas to the internal standard peak area

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of thiamine hydrochloride in the portion of Thiamine Hydrochloride taken:

Result = (R_U/R_S) × (C_S/C_U) × 100

R_U = internal standard ratio (peak area of thiamine/peak area of the internal standard) from the Sample solution

R_S = internal standard ratio (peak area of thiamine/peak area of the internal standard) from the Standard solution

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

C_U = concentration of Thiamine Hydrochloride in the Sample solution (mg/mL)

Acceptance criteria: 98.0%–102.0% on the anhydrous basis

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.2%

Limit of Nitrate

Sample solution: 20 mg/mL of Thiamine Hydrochloride

Analysis: To 2 mL of the Sample solution add 2 mL of sulfuric acid. Cool, and superimpose 2 mL of ferrous sulfate TS.

Acceptance criteria: No brown ring is produced at the junction of the two layers.

Related Compounds

Solution A, Solution B, and Mobile phase: Proceed as directed in the Assay.

Sample solution: 1.0 mg/mL of Thiamine Hydrochloride in Mobile phase

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.0-mm × 15-cm; packing L1

Flow rate: 0.75 mL/min

Injection size: 10 μL

Analysis

Sample: Sample solution

Allow the Sample solution to elute for NLT three times the retention time of the main peak.

Calculate the percentage of total secondary peaks in the portion of Thiamine Hydrochloride taken:

Result = (r_U/r_T) × 100

r_U = sum of the areas of all the peaks, except that of the thiamine peak

r_T = sum of the areas of all the peaks

Acceptance criteria: NMT 1.0%

5 SPECIFIC TESTS

pH 〈791〉

Sample solution: 10-mg/mL solution

Acceptance criteria: 2.7–3.4

Water Determination, Method I〈921〉: NMT 5.0%

Absorbance of Solution

Sample solution: 100 mg/mL in water. Filter through a fine-porosity, sintered-glass funnel.

Blank: Water

Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV-Vis

Analytical wavelength: 400 nm

Cell: 1 cm

Analysis

Samples: Sample solution and Blank

Determine the absorbance of the Sample solution against that of the Blank.

Acceptance criteria: NMT 0.025

6 ADDITIONAL REQUIREMENTS

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

USP Reference Standards 〈11〉

USP Thiamine Hydrochloride RS