Thiamine Hydrochloride (Vitamin B1)

Grades and forms

Thiamine hydrochloride is the more water-soluble of the two main vitamin B1 salts used in EU food supplements. The other is thiamine mononitrate. The choice between them usually comes down to moisture: the hydrochloride suits liquids and soluble formats, while the mononitrate is often preferred in dry blends.

Thiamine hydrochloride powder is bought to food-grade specifications or to pharmacopoeia grades. The grade decides which tests and limits the certificate of analysis reports. Particle size matters too. Fine powder blends more evenly at low inclusion rates, while coarser crystalline material flows better in direct compression.

Vitamin B1 is used at milligram levels, so many manufacturers add it through a vitamin premix rather than weighing the pure salt into each batch. SoleChem sends the specification sheet and the certificate of analysis with its quote; state the grade and particle size you need in the quote form. The vitamin B1 guide covers both salts side by side.

EU regulatory status

Thiamin hydrochloride is listed as a form of vitamin B1 in Annex II of Directive 2002/46/EC, so it may be used in food supplements across the EU. Thiamin mononitrate is listed in the same annex. Annex II of Regulation (EC) No 1925/2006 lists both salts for addition to other foods.

Annex I of the Directive lists the vitamin as “Vitamin B1” with the unit mg. The label therefore declares the amount of thiamin, not the mass of the salt. The labelling guide explains how this works in practice, and the permitted forms guide covers the Annex II list.

The Directive provides for EU maximum levels, but none have been adopted for vitamin B1. Member states apply their own rules, and these may differ. See maximum levels by EU country before setting a label claim for several markets. For authorised claim wording, consult the EU Register of nutrition and health claims and the health claims guide.

Formulation notes

• Solubility and moisture. Thiamine hydrochloride dissolves readily in water and gives an acidic solution. It is more hygroscopic than the mononitrate. Keep containers sealed and process in low-humidity rooms.
• pH and heat. Thiamine is most stable under acidic conditions. Losses rise at neutral to alkaline pH and on heating, which matters in liquids, gummies and heat-processed formats.
• Incompatibilities. Sulfites cleave the thiamine molecule, so avoid sulfite-containing ingredients. Alkaline salts such as magnesium oxide or calcium carbonate can increase losses in moist blends.
• Taste and odour. The salt has a bitter taste and a characteristic sulfurous odour. Both can show in chewables, gummies and drink powders.
• Low-dose uniformity. In tablets and capsules, pre-blend the salt with a carrier by geometric dilution to secure content uniformity.
• Overage. Set any overage from your own stability data; the overage calculator handles the arithmetic.

Salt arithmetic

Both salts carry one thiamine cation per formula unit. The hydrochloride (337.3 g/mol) is heavier than the mononitrate (327.36 g/mol) by a factor of 337.3 ÷ 327.36 = 1.030. A formula that switches from 5.00 mg of mononitrate needs 5.00 × 1.030 = 5.15 mg of hydrochloride for the same thiamin.

To convert salt mass into declared thiamin, use the assay basis and water content stated on the specification sheet. The elemental content calculator applies the same method.

How it compares to other forms

B-complex products often pair the salt with riboflavin and pyridoxine hydrochloride. Confirm stability of the combined premix in the final format.