HG/T 6247-2023: Reading China's Biosynthetic UDCA Standard
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A certificate of analysis from a Chinese supplier often carries a standard number in the specification header, and a buyer scanning for pharmacopoeial references reads past it. The number is not decoration. It tells you which document the specification comes from, and therefore what the supplier is actually claiming.
HG/T 6247-2023, the chemical industry standard for biosynthetic ursodeoxycholic acid, is a useful case because it sits close enough to a pharmacopoeia to be mistaken for one.
What the letters mean
Chinese standards carry a prefix that identifies the issuing layer, and the layer determines what the document can and cannot do.
| Prefix | Layer | Typical role |
|---|---|---|
| GB | National standard | Mandatory where law references it, otherwise widely adopted |
| GB/T | Recommended national standard | Voluntary basis, often adopted by contract |
| HG/T | Recommended chemical industry standard | Sector specification for industrial and chemical products |
| ChP | Pharmacopoeia of the People's Republic of China | Legal standard for medicinal products in China |
| Enterprise standard | Individual company | What a specific plant commits to, sometimes tighter than any of the above |
HG/T is a recommended industry standard, issued by the Ministry of Industry and Information Technology. It fixes five measured properties for the substance plus an appearance requirement, gives a test method for each, and closes with rules for marking, packaging, transport and storage. It is a serious document, drafted through a formal process, and it is not a pharmacopoeia.
What HG/T 6247-2023 covers
The standard addresses biosynthetic ursodeoxycholic acid: material prepared from chenodeoxycholic acid or 7-ketolithocholic acid by whole-cell synthesis or enzymatic processing. That scope matters, because the route determines the impurity profile, and a standard written around one route describes what that route produces. Note what the scope does not say. It does not claim the whole synthesis is biological, only the step the title names.
Its publication date is 20 December 2023 with implementation from 1 July 2024, which places it inside the period when biosynthetic capacity was expanding quickly. A standard appearing at that moment is doing something specific: giving buyers and sellers a common reference for a product that previously had none beyond enterprise specifications.
The requirements sit in one table, clause 4, and the table is short.
| Item | Limit | Method |
|---|---|---|
| Appearance | White or almost white powder | Visual |
| Initial melting point | Not below 200 °C | GB/T 617 |
| Ursodeoxycholic acid (assay) | Not less than 95.0% | HPLC, external standard |
| Specific rotation | +59.0 to +62.0, in the standard's units | GB/T 613 |
| Loss on drying | Not more than 1.0% | GB/T 6284 |
| Residue on ignition | Not more than 0.5% | GB/T 7531, ignited at 750 °C |
Read the third row twice. A floor of 95.0% is a chemical-sector figure, agreed between a plant and an industrial customer. Whatever floor the pharmacopoeial monograph for your market sets, the distance between the two numbers is the specification work that nobody else will do for you. What the table does not contain matters just as much: no related-substances limits, no heavy metals, no microbiological limits. A buyer who needs those rows supplies them from the monograph, or writes them into a contract specification.
What the standard also does not do is establish suitability for a medicinal product, because that judgement belongs to the pharmacopoeia and to the regulator.
The distinction that matters commercially
Three sentences that sound similar and are not.
"Conforms to HG/T 6247-2023." The material meets a Chinese industry specification for a chemical product.
"Conforms to the Ph. Eur. monograph." The material meets the European pharmacopoeial standard for a substance used in medicinal products in Europe.
"Covered by a certificate of suitability." The substance, made at a named site, has been assessed against that monograph by the European authority responsible.
Only the third supports a European marketing authorisation without further documentation. The first two describe quality against a specification; they do not describe regulatory status.
This is why a supplier can be entirely honest and still confusing. Material meeting HG/T 6247-2023 may also meet the European monograph, and the two claims are separate. A buyer who reads the industry standard as a pharmacopoeial claim has made an inference the document never made. For the European side of that distinction, see what an EP grade claim actually means.
How to use the standard number properly
Four steps take ten minutes and remove most of the ambiguity.
- Read the prefix. GB, GB/T, HG/T and ChP answer different questions, and the prefix is the fastest way to know which.
- Check that the standard is current. Chinese standards are revised and superseded, and the metadata is publicly searchable by number through the national standards platform.
- Compare it with the specification you need, line by line. Where the standard has no limit for a parameter your product requires, the gap is yours to close, not the standard's to fill. The method for that comparison is in supplier specification against in-house specification.
- Ask which document governs the batch. A COA can cite an industry standard while the plant releases against an enterprise standard that is tighter. Knowing which one produced the numbers on the page is the point.
Why enterprise standards sometimes matter more
In practice, many Chinese plants release against an enterprise standard that is stricter than the industry standard, because customers ask for more than the published document requires. The industry standard sets a floor that the sector accepts; the enterprise standard describes what the plant actually commits to.
A supplier who can show the relationship between the two is easier to qualify than one who can only produce the published document. The first has a specification system. The second has a certificate.
For how the numbers on the page hang together, see how to read a UDCA certificate of analysis.
The question to ask a Chinese supplier
Not "does it meet the standard", which invites a yes. Ask which standard appears on the certificate, whether that standard is current, whether an enterprise standard sits behind it, and what the material's regulatory status is in the market you are supplying.
Four answers, and the fourth is the only one that speaks to your registration. It is also the one most often answered with the first.
Primary sources: the European Pharmacopoeia for the monograph that governs European use, EDQM certification for how that monograph becomes a certificate, and USP for the corresponding documentary standards in the United States.
Frequently asked questions
Is HG/T 6247-2023 a pharmacopoeia?
No. It is a recommended chemical industry standard describing a product for the chemical sector. A pharmacopoeia is a legal standard for medicinal products, and in China that role belongs to the ChP.
Can I use material meeting HG/T 6247-2023 in a European product?
The standard does not decide that. What decides it is whether the material meets the pharmacopoeial monograph and what documentation supports it in your marketing authorisation. Meeting an industry standard is a starting point, not a regulatory status.
What limits does HG/T 6247-2023 actually set?
Appearance plus five measured properties: initial melting point not below 200 °C, assay not less than 95.0%, specific rotation +59.0 to +62.0 in the standard's units, loss on drying not more than 1.0%, and residue on ignition not more than 0.5%. Just as important is the absence: no related-substances limits, no heavy metals, no microbiological limits.
How do I confirm a Chinese standard is still current?
The metadata for national and industry standards is publicly searchable by number through the national standards platform, including publication and implementation dates and any superseding document.
What is an enterprise standard and why does it matter?
It is the specification a specific plant commits to, and it is frequently tighter than the published industry standard because customers ask for more. It is often the document that actually governs release.
Does citing a standard on a COA constitute a compliance claim?
It is a claim that the batch was tested against that specification. It is not a claim of pharmacopoeial compliance, and it is not a statement about regulatory status in any market.