Active pharmaceutical ingredient (revision 26)

An active pharmaceutical ingredient (API) is a substance intended to be used in the manufacture of a medicinal product and to furnish pharmacological activity in it. The term is a regulatory category rather than a chemical one: the same molecule is an API when destined for a medicine and is not when destined for laboratory research.^[1]

That distinction determines which requirements apply. API manufacture is subject to GMP and to registration in many jurisdictions; the same chemistry performed for research supply is not.^[1]

The practical consequence is that "pharmaceutical grade" applied to a research chemical is not a defined term. Where it means anything, it means the supplier's own grade designation, and what it covers is whatever the accompanying specification says.^[2]

Guidance for APIs covers the same ground as finished-product GMP, adapted to bulk substance: materials, process controls, validation, records, and the point in a process at which GMP begins to apply — which for a synthetic API is generally the introduction of the starting material into the process.^[1]

Registration mechanisms vary. A drug master file allows a manufacturer to submit confidential process detail to a regulator and to authorise a customer to reference it; other jurisdictions use certificates of suitability or direct registration.

None of this applies to a research chemical. A supplier may nonetheless hold registrations for other product lines, and such a registration is a checkable claim in the sense described at Good manufacturing practice — with a registrant, a number and a scope.^[3] Documents submitted to this wiki that assert such registrations vary widely in whether they supply those particulars.^[4]

The first three are checkable because each names something external — a regulation, a monograph, a specification. The last two are supplier designations, and their meaning is exactly and only what the accompanying specification states.^[2]

This is not a criticism of suppliers using the terms. It is an observation that a grade name is not a specification, and that the question worth asking of any grade claim is which document defines it.

The same molecule, made by the same chemistry, in the same facility, may be an API for one customer and a research chemical for another. The difference lies in the quality system applied and the documentation generated, not in the atoms.^[1]

This is why claims of the form "made on the same line as pharmaceutical material" are hard to evaluate. They may be true and yet say nothing about whether the batch in question was made under the same controls, since GMP applies to a process and its records rather than to a room.

For a purchaser reading a certificate, the useful question is unchanged: what does this document report, and against what specification? A grade name answers neither. See Certificate of analysis.^[2]

• Good manufacturing practice
• Drug master file
• Certificate of analysis
• ISO 9001
• Research use only