NAD (CAS 53-84-9): Aqueous Solution vs Biotransformation Grade vs Food Grade

NAD (CAS 53-84-9) is quoted in three commercial forms: an 85% min aqueous solution, a 98% min biotransformation-grade powder and a 99% min food-grade powder. Buyers routinely compare those three numbers as if they were points on the same scale, and that is where money is lost. The three figures sit on different bases, the three forms have different freight and storage costs, and only one of them carries a food-grade documentation package. This article sets out what actually differs and how to compare quotes properly.

1. What the three numbers really mean

Form	Assay figure	Basis	What 1 kg delivers
Aqueous solution	85% min	Per kg of solution	At least 850 g of NAD, plus water and the balance of the mother liquor
Biotransformation-grade powder	98.0% min	Dry basis, HPLC	At least 980 g of NAD per kg of dry material – before moisture is accounted for
Food-grade powder	99.0% min	Dry basis, HPLC	At least 990 g of NAD per kg of dry material

Two separate distortions hide in this table. First, the solution figure includes the water: 85% of a solution is not 85% of a powder. Second, the powder figures are on a dry basis – the lot you receive will contain water (typically stated separately as water content or loss on drying), so the as-received content is slightly lower than the headline figure. A 98% dry-basis powder at 3% water delivers about 95% as received.

2. The cost comparison that actually works

Step	Calculation	Example
1. Convert the assay to as-received content	assay (dry basis) x (1 – water content)	98% x (1 – 0.03) = 95.1%
2. Convert the solution figure to the same footing	assay (per kg solution) – no further correction	85% as received
3. Divide the price by the delivered NAD content	price per kg / content	Powder at USD 100/kg -> 105 USD per kg of NAD; solution at USD 80/kg -> 94 USD per kg of NAD
4. Add the cost of the water you ship	freight per kg x (1 – content)	Shipping 15% water is not free at air-freight rates

Run those four steps and the ranking often reverses. The solution looks 13-14% cheaper per kilogram at the headline level; per kilogram of delivered NAD, plus freight of the water, it can be the more expensive option. Equally, for a plant that would otherwise have to dissolve and filter powder, the solution can still win on total cost of use. The point is to decide it with numbers, on one basis, not on the headline percentage.

3. Stability and what each form tolerates

Stress	Powder	Aqueous solution
Moisture	Hygroscopic – caking and hydrolysis if the container is left open	Already in water; the relevant risk is microbial growth and slow hydrolysis
Heat	Tolerates ambient transit better; store at -20 °C for long-term inventory	Keep at 2-8 °C; do not freeze and thaw repeatedly
Light	Protect from light	Protect from light; amber or opaque packaging
pH	Stable as a dry solid; solutions must be near neutral	The concentrate is acidic – check the pH and neutralise as your process requires
Cold weather	No issue	Concentrates can crystallise or become viscous below about 5 °C – plan drum heating

NAD is hydrolysed by both acid and alkali, and the glycosidic bond between the nicotinamide ribose and the rest of the molecule is the weak point. In practice this means: prepare solutions at pH 6.0-7.5, hold them cold, and do not carry a solution in inventory for months when the powder would keep.

4. Grade is not permission

The 99% food-grade powder is a material specification, not a regulatory authorisation. Whether NAD may be used in a food or supplement in your market is a separate question answered by that market’s rules, and the answer varies. In several jurisdictions NAD itself is not a permitted food ingredient even though material of food-grade quality is traded. Do not let a grade name substitute for a regulatory check: confirm the position for the destination and the end use, and write that confirmation into your supplier qualification file. Nothing in this article is a health claim, and NAD is not offered with therapeutic or anti-ageing claims.

5. Choosing between the three, by situation

Situation	Recommended form	Reason
Continuous biocatalytic reduction, dosing into a bioreactor	Aqueous solution	No dissolution step, no dust, dosing is gravimetric and repeatable
Enzyme assays and reagent kits	Biotransformation-grade powder	You control the buffer and the final concentration; no water to ship or store
Inventory held for more than a few weeks	Powder	Long-term stability at -20 °C; smaller storage footprint
Nutraceutical or food application, where permitted	Food-grade powder	Food-grade documentation package; the only grade with the corresponding limits
Pilot scale, uncertain demand	Powder	You can make up solution as needed instead of committing to a drum of liquid

6. What to specify on the purchase order

Form and assay basis, written out: “aqueous solution, 85% min per kg of solution” or “powder, 98.0% min dry basis, HPLC”.
Water content for powder lots, and pH for solution lots – two figures that decide whether the delivered content matches the quote.
Assay method: HPLC versus enzymatic. They are not interchangeable, and a certificate that does not say which method was used cannot be compared with another supplier’s.
Microbial limits for solution lots, where the material will enter a sterile or cell-based process.
Packaging: drum, flexibag or bottle; fill volume; and whether the pack is single-use.

7. Packaging and supply

Powder is supplied in foil-lined bags or fibre drums with an inner liner, and solution in HDPE drums or flexibags. Both are agreed against your process: the pack size should match a working batch, because a partly used drum of solution is a stability liability rather than an asset. Cold-chain arrangements (2-8 °C for solution, -20 °C option for powder held long term) are quoted with the material, and each lot ships with a certificate of analysis and safety data sheet. Where an application is regulated, ask for the documentation package in the enquiry rather than after the order – it affects which grade you should be quoted in the first place.

8. Five mistakes that show up in incoming goods

Comparing 85% with 98% directly. Different bases; convert first.
Ignoring water content on powder. A 98% dry-basis figure with 5% water is a 93% as-received material.
Treating food grade as a licence. It is a specification, not an authorisation.
Freezing solution in winter transit. Ask what the shipping temperature and the thaw instructions are.
Accepting a certificate without the method. HPLC or enzymatic, dry basis or as-received – insist that the COA says which.

Products in this family

PolyBlueChem supplies NAD (CAS 53-84-9) as 85% min aqueous solution, 98.0% min biotransformation-grade powder and 99.0% min food-grade powder, with per-batch COA and SDS and FOB/CIF delivery. Send your form, assay basis, quantity and destination for a quotation on the basis you actually buy on.