Thiamine 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

Thiamine Hydrochloride Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of thiamine hydrochloride.

2 IDENTIFICATION

A.

Sample solution: Triturate a quantity of powdered Tablets, equivalent to 10 mg of thiamine hydrochloride, with 10 mL of 0.5 N sodium hydroxide, and filter.

Analysis: To 5 mL of the Sample solution add 0.5 mL of potassium ferricyanide TS and 5 mL of isobutyl alcohol, shake the mixture vigorously for 2 min, and allow the liquid layers to separate. Illuminate from above by a vertical beam of UV light, and observe the air–liquid meniscus at a right angle to this beam.

Acceptance criteria: The air–liquid meniscus shows a vivid blue fluorescence, which disappears when the mixture is slightly acidified, but reappears when it is again made alkaline.

B.

Sample solution: Triturate a quantity of powdered Tablets, equivalent to 10 mg of thiamine hydrochloride, with 10 mL of water, and filter.

Analysis 1: To 2 mL of the Sample solution add iodine TS.

Acceptance criteria 1: A red-brown precipitate is formed.

Analysis 2: To 2 mL of the Sample solution add mercuric chloride TS.

Acceptance criteria 2: A white precipitate is formed.

Analysis 3: Identification Tests—General 〈191〉, Chloride

Acceptance criteria 3: Meet the requirements

C.

Sample solution: Use the remainder of the Sample solution from IdentificationB.

Analysis: Add 1 mL of lead acetate TS and 1 mL of 2.5 N sodium hydroxide.

Acceptance criteria: A yellow color is produced. Heat the mixture for several minutes on a steam bath: the color changes to brown, and, on standing, a precipitate of lead sulfide separates.

3 ASSAY

Thiamine Assay 〈531〉, Chemical Methods, Procedure 1

Sample solution: Place NLT 20 Tablets in a flask of suitable size, half fill the flask with 0.2 N hydrochloric acid, and heat on a steam bath, with frequent agitation, until the Tablets have dissolved or have disintegrated so that a uniform dispersion is obtained. Cool, transfer the contents of the flask to a volumetric flask, and dilute with 0.2 N hydrochloric acid to volume. If the mixture is not clear, either centrifuge it or filter it through paper known not to adsorb thiamine. Dilute a portion of the clear solution with 0.2 N hydrochloric acid to obtain a 0.2-μg/mL solution of thiamine hydrochloride.

Analysis: Proceed as directed in the chapter.

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉, Procedure, Apparatus 1 and 2, Immediate-Release Dosage Forms, Procedure for a pooled sample for immediate-release dosage forms

Medium: Water; 900 mL

Apparatus 2: 50 rpm

Time: 45 min

Standard solution: A known concentration of USP Thiamine Hydrochloride RS in Medium

Sample solution: Filtered portion of the solution under test, suitably diluted with the Medium if necessary

Mobile phase: A mixture of methanol, glacial acetic acid, and water (27:1:73) containing 1.40 mg/mL of sodium 1-hexanesulfonate

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 280 nm

Column: 3.9-mm × 30-cm; packing L1

Flow rate: 1 mL/min

Injection volume: 10 μL

System suitability

Sample: Standard solution

Suitability requirements

Relative standard deviation: NMT 3.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of thiamine hydrochloride dissolved:

Result = (r_U/r_S) × (C_S × D × V/L) × 100

r_U = peak area of thiamine from the Sample solution

r_S = peak area of thiamine from the Standard solution

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

D = dilution factor for the Sample solution

V = volume of Medium, 900 mL

L = labeled claim of thiamine hydrochloride (mg/Tablet)

Tolerances: NLT 75% (Q) of the labeled amount of thiamine hydrochloride  is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

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

USP Reference Standards 〈11〉

USP Thiamine Hydrochloride RS