Why choose thiamine mononitrate over thiamine HCl for dry formulations?

Thiamine mononitrate is non-hygroscopic, meaning it does not absorb moisture from the air during blending, tableting, or storage. This prevents caking, degradation, and stability loss in dry formulations. Thiamine HCl, by contrast, is hygroscopic and can absorb moisture leading to hydrolysis and potency loss. Mononitrate is the standard for flour enrichment, breakfast cereals, dry powder blends, effervescent tablets, and infant formula where prolonged shelf stability in dry environments is required.

What are mandated flour fortification programs and why do they use thiamine mononitrate?

Many countries mandate thiamine fortification of wheat flour as a public health measure to prevent beriberi and thiamine deficiency. The US, Canada, UK, and over 85 countries have mandatory or voluntary flour enrichment programs. Thiamine mononitrate is the universally preferred form for flour fortification because: (1) it is non-hygroscopic and stable during flour storage, (2) it does not interact with other flour enrichment nutrients (iron, niacin, riboflavin, folic acid), and (3) it withstands baking temperatures with minimal degradation. Typical fortification levels are 2.5-6.4 mg/kg flour.

What is the thiamine content difference between mononitrate and HCl salt forms?

Thiamine mononitrate (MW 327.36) delivers approximately 81.1% thiamine base by weight (265.36/327.36). Thiamine HCl (MW 337.27) delivers approximately 89.2% thiamine base. When formulating, dose adjustments are needed when switching between salt forms — a 100 mg thiamine HCl tablet delivers approximately 89.2 mg thiamine base, while 100 mg thiamine mononitrate delivers 81.1 mg. Most pharmacopoeias express potency as thiamine hydrochloride or thiamine nitrate content, not as free thiamine base.

Vitamin B1 (Thiamine Mononitrate) | CAS 532-43-4 | Nutrition Ingredient Supplier China

Name: Vitamin B1 (Thiamine Mononitrate)
SKU: 532-43-4
Availability: InStock

Vitamin B1 (Thiamine Mononitrate) molecular structure

Quick Facts

CAS Number	532-43-4
Molecular Formula	C₁₂H₁₇N₅O₄S
Molecular Weight	327.36
Pharmacopoeia	BP/USP
Packaging	25 KG/DRUM

BP Grade USP Grade

Product Overview

Thiamine mononitrate is the nitrate salt form of Vitamin B1, developed to address the key limitation of the hydrochloride salt: hygroscopicity. While the HCl salt absorbs atmospheric moisture, causing caking and degradation in dry blends, the mononitrate salt remains free-flowing under ambient conditions. This single property difference transformed global food fortification, enabling thiamine to be stably incorporated into flour, breakfast cereals, infant formulas, and dry supplement blends with long ambient shelf lives.

The shift from polished rice to refined wheat flour as the global staple carbohydrate created a new public health challenge in the early 20th century. Just as polished rice stripped thiamine and caused beriberi in Asia, roller-milled white flour removed the B-vitamin-rich bran and germ. Mandatory flour enrichment programs, beginning in the US in 1941 and now active in over 85 countries, specifically selected thiamine mononitrate as the standard fortificant because of its non-hygroscopic nature and compatibility with other enrichment nutrients (iron, niacin, riboflavin, folic acid) during flour storage and baking.

Chemically, thiamine mononitrate (C12H17N5O4S, MW 327.36) contains 81.1% thiamine base by weight, slightly less than the 89.2% delivered by the HCl salt. However, the stability advantage far outweighs the minor potency difference for dry formulations. The mononitrate withstands baking temperatures with minimal degradation, maintains potency through years of ambient storage, and does not cause vitamin-vitamin interactions in multi-nutrient premixes — all critical benefits for large-scale food manufacturing and global distribution.

As of mid-2026, thiamine mononitrate demand is driven by expanding mandatory flour fortification programs in Africa and Southeast Asia, increasing infant formula production in China and India, and growing B-complex supplement consumption worldwide. Like the HCl salt, global API production is concentrated in China (Zhejiang, Jiangsu, Hubei), with identical supply chain dynamics. KingWish supplies BP/USP-grade thiamine mononitrate for food fortification, dietary supplements, infant formula, and sports nutrition applications, supporting manufacturers in over 100 countries.

Quality Specifications

Assay (HPLC)	99.0-101.0% (dried basis), per BP/USP monograph
pH (2% aqueous)	6.0-7.5, per BP/USP
Loss on Drying	≤ 1.0%
Related Substances	Individual impurity ≤ 0.3%, total impurities ≤ 1.0%
Heavy Metals	≤ 10 ppm
GMP Status	Manufactured under ICH Q7 GMP conditions

Applications

Food Fortification: Flour enrichment, breakfast cereals, rice fortification, and staple food nutrition programs
Dietary Supplements: B-complex tablets, multivitamin capsules, effervescent tablets, and individual B1 supplements
Infant Formula: Essential micronutrient in infant and follow-on formula products meeting CODEX standards
Sports Nutrition: Energy metabolism support in sports drinks, protein bars, and recovery supplements
Flour Enrichment: Meets mandatory flour fortification requirements in numerous countries

Sourcing Thiamine Mononitrate: Key Checks

Documentation

Request CoA with HPLC assay, loss on drying (≤1.0%), pH (6.0-7.5), and related substances profile. For food applications, confirm compliance with FCC or food-grade specifications. For infant formula, additional microbiological testing (TAMC, TYMC, pathogens) is typically required. DrugBank reference

Red Flags

pH outside 6.0-7.5 (may indicate degradation or contamination), elevated loss on drying (>1.0%), presence of chloride (indicating HCl salt contamination), free-flow issues suggesting moisture exposure, and certificates without batch-specific test data.

Packaging & Logistics

Standard: 25 KG/DRUM with PE liner. Store at room temperature, protected from light. While non-hygroscopic, extended exposure to high humidity (>75% RH) should still be avoided. Shelf life typically 36 months. Custom packaging including smaller drums or cartons available.

Market Context

Thiamine mononitrate and HCl share the same upstream supply chain and manufacturers — most producers make both salt forms. Market dynamics are identical: Chinese production dominance (~80-85%), price volatility driven by environmental inspections, and periodic supply tightness during regulatory enforcement actions. Dual qualify both salt forms if your portfolio uses both.

Frequently Asked Questions

Thiamine mononitrate is non-hygroscopic — it does not absorb moisture from the air during blending, tableting, or storage. This prevents caking, hydrolysis, and potency loss in dry formulations. Thiamine HCl, by contrast, is hygroscopic and can absorb ambient moisture leading to degradation and free-flow issues. Mononitrate is the standard choice for flour enrichment, breakfast cereals, dry powder blends, effervescent tablets, and infant formula — any application where prolonged shelf stability in dry environments is required.

Over 85 countries have mandatory or voluntary flour enrichment programs requiring thiamine fortification to prevent beriberi and thiamine deficiency at the population level. The US program began in 1941; the UK mandated it in 1953. Thiamine mononitrate is universally preferred because: (1) it is non-hygroscopic and stable during months of flour storage, (2) it does not chemically interact with other enrichment nutrients (iron, niacin, riboflavin, folic acid), and (3) it withstands baking temperatures (180-220 degrees C) with minimal degradation. Typical fortification levels are 2.5-6.4 mg thiamine per kg flour, depending on national regulations.

Thiamine mononitrate (MW 327.36) delivers approximately 81.1% thiamine base by weight. Thiamine HCl (MW 337.27) delivers approximately 89.2% thiamine base. When switching between salt forms in a formulation, dose adjustment is required: 100 mg of thiamine HCl provides ~89.2 mg thiamine base, while 100 mg of thiamine mononitrate provides ~81.1 mg. Most pharmacopoeia monographs express potency as thiamine hydrochloride or thiamine nitrate content, not as free thiamine base — always confirm which convention your specification uses.

Thiamine mononitrate has significantly lower water solubility (~2.7 g/100 mL at 25 degrees C) compared to thiamine HCl (>100 g/100 mL). This limits its use in concentrated liquid formulations. For liquid supplements, oral solutions, syrups, and injectable products, thiamine HCl is the standard choice. However, thiamine mononitrate can be formulated into suspensions, low-concentration liquid products (within its solubility limit), and products where slower dissolution kinetics are desirable for modified-release effects.

Standards: BP/USP | CAS: 532-43-4 | Quality data verified against pharmacopoeia monograph COA and MSDS available | DrugBank | July 2026