Edition: BP 2025 (Ph. Eur. 11.6 update)
Action and use
Vitamin B1.
DEFINITION
Thiamine Injection is a sterile solution of Thiamine Hydrochloride in Water for Injections.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of thiamine hydrochloride, C12H17ClN4OS,HCl
95.0 to 105.0% of the stated amount.
CHARACTERISTICS
A colourless or almost colourless solution.
IDENTIFICATION
A. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Use the injection, diluted with water, if necessary, to contain 0.1% w/v of Thiamine Hydrochloride.
(2) 0.1% w/v of thiamine mononitrate BPCRS in water.
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating cellulose F254.
(b) Use the mobile phase as described below.
(c) Apply 2 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air, heat at 105° for 30 minutes, spray with a mixture of equal volumes of a 0.3% w/v solution of potassium hexacyanoferrate(III) and a 10% w/v solution of sodium hydroxide and examine under ultraviolet light (365 nm).
MOBILE PHASE
15 volumes of glacial acetic acid, 25 volumes of water and 60 volumes of butan-1-ol.
CONFIRMATION
The principal spot in the chromatogram obtained with solution (1) corresponds in position and colour to that in the chromatogram obtained with solution (2).
B. To a volume containing 20 mg of Thiamine Hydrochloride diluted, if necessary, to 10 mL with water, add 2 mL of 1M acetic acid and 1.6 mL of 1M sodium hydroxide, heat in a water bath for 30 minutes and cool. Add 5 mL of 5M sodium hydroxide, 10 mL of dilute potassium hexacyano-ferrate(III) solution and 10 mL of butan-1-ol and shake vigorously for 2 minutes. The upper layer shows an intense light blue fluorescence on exposure to ultraviolet light. Repeat the test but adding 0.9 mL of 1M sodium hydroxide and 0.2 g of sodium sulfite in place of the 1.6 mL of 1M sodium hydroxide. Not more than a slight fluorescence is produced.
C. To a mixture of 0.1 mL of nitrobenzene and 0.2 mL of sulfuric acid add a volume of the injection containing 5 mg of Thiamine Hydrochloride. Allow to stand for 10 minutes, cool in ice and add slowly with stirring 5 mL of water followed by 5 mL of 10M sodium hydroxide. Add 5 mL of acetone and allow to stand. No violet colour is produced in the upper layer.
TESTS
Acidity
pH, 2.8 to 3.4, Appendix V L.
ASSAY
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) Dilute a volume of the injection containing 0.1 g of Thiamine Hydrochloride to 100 mL with 0.1M hydrochloric acid and further dilute 5 mL to 100 mL with water.
(2) 0.005% w/v of thiamine mononitrate BPCRS in 0.005M hydrochloric acid.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (10 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Nucleosil C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 2 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 244 nm.
(f) Inject 20 µL of each solution.
MOBILE PHASE
Dissolve 1 g of sodium heptane sulfonate in a mixture of 180 mL of methanol and 10 mL of triethylamine, diluting to 1000 mL with water and adjusting the pH to 3.2 with orthophosphoric acid.
DETERMINATION OF CONTENT
Calculate the content of C12H17ClN4OS,HCl using the declared content of C12H17N5O4S in thiamine mononitrate BPCRS. Each mg of C12H17N5O4S is equivalent to 1.030 mg of C12H17ClN4OS,HCl.
STORAGE
Thiamine Injection should be protected from light.
When vitamin B1 injection is prescribed or demanded, Thiamine Injection shall be dispensed or supplied.
