Thiamine Hydrochloride Tablets
» Thiamine Hydrochloride Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C12H17ClN4OS·HCl.
Packaging and storage— Preserve in tight, light-resistant containers.
A: Triturate a quantity of powdered Tablets, equivalent to about 10 mg of thiamine hydrochloride, with 10 mL of 0.5 N sodium hydroxide, and filter. Using a 5-mL portion of the filtrate, proceed as directed in Identification test B under Thiamine Hydrochloride Injection, beginning with “then add 0.5 mL of potassium ferricyanide TS”: the specified reaction is observed.
B: Triturate a quantity of powdered Tablets, equivalent to about 10 mg of thiamine hydrochloride, with 10 mL of water, and filter: treated separately, 2-mL portions of the filtrate yield a red-brown precipitate with iodine TS and a white precipitate with mercuric chloride TS, and respond to the tests for Chloride 191.
C: To the remainder of the filtrate prepared for the preceding test add 1 mL of lead acetate TS and 1 mL of 2.5 N sodium hydroxide: 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.
Dissolution, Procedure for a Pooled Sample 711
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Time: 45 minutes.
Procedure— Determine the amount of C12H17ClN4OS·HCl dissolved, employing the procedure set forth in the Assay for niacin or niacinamide, pyridoxine hydrochloride, riboflavin, and thiamine, Method 1 under Water-Soluble Vitamins Tablets using filtered portions of the solution under test, suitably diluted with Dissolution Medium if necessary, in comparison with a Standard solution having a known concentration of USP Thiamine Hydrochloride RS in the same Medium.
Tolerances— Not less than 75% (Q) of the labeled amount of C12H17ClN4OS·HCl is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Standard preparation— Prepare as directed for Standard Preparation under Thiamine Assay 531.
Assay preparation— Place not fewer than 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 quantitatively and stepwise with 0.2 N hydrochloric acid to obtain a solution containing about 0.2 µg of thiamine hydrochloride per mL. Using this as the Assay Preparation, proceed as directed for Procedure under Thiamine Assay 531.
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Topic/Question Contact Expert Committee
Monograph Curtis Phinney

(DSN05) Dietary Supplements - Non-Botanicals
Reference Standards Lili Wang, Technical Services Scientist
711 Margareth R.C. Marques, Ph.D.
Senior Scientist
(BPC05) Biopharmaceutics05
USP32–NF27 Page 3719
Pharmacopeial Forum: Volume No. 30(1) Page 190