Buyers assume excipients are made under the same controls as APIs. They usually are not, and the gap is where excipient supply chain incidents originate.
Excipient manufacture is not held to API GMP standards by default, because many excipients are produced in large volumes for food, cosmetic and industrial customers with pharmaceutical grade forming a small segregated portion. The IPEC-PQG Good Manufacturing Practices guide was written specifically for excipient manufacture and addresses change control, cross contamination between grades and traceability through distribution.
The assumption behind most excipient purchasing is that a pharmaceutical ingredient is made under pharmaceutical conditions. For active ingredients that is broadly true. For excipients it often is not, and the reason is structural rather than negligent.
Many excipients are produced in large volumes for industries other than pharmaceuticals. The same lactose, cellulose, glycol or stearate may serve food, cosmetic and industrial customers, with the pharmaceutical grade representing a small fraction of output. The plant is engineered around the majority use, and pharmaceutical requirements are applied to a segregated portion of production.
That is a legitimate model. It also means the controls around your material depend on how carefully that segregation is managed, which is not something a monograph tells you.
The joint IPEC-PQG Good Manufacturing Practices guide was written specifically for excipient manufacture, precisely because API GMP does not map cleanly onto plants of this type. It addresses the things that actually go wrong in excipient supply: change control, contamination and cross contamination between grades, traceability through the chain, and management of the point where general production becomes pharmaceutical production.
A supplier certified against it has been assessed on the risks specific to excipients. A supplier who simply states "GMP" may mean something quite different, or may mean the certification of a different product line entirely.
The distribution chain is the weak point. Excipients frequently reach buyers through distributors who repack, relabel or split lots. Every one of those steps is an opportunity for the chain of custody to break. The most serious excipient incidents in pharmaceutical history have involved substituted or mislabelled material moving through distribution, not manufacturing failure at source. Knowing who repacked your material, and under what quality system, is not a formality.
By the time an excipient reaches your quality department it has already been selected, priced and ordered. The questions above only have leverage before that point. This is the reasoning behind treating excipients as a distinct sourcing discipline on our excipients page rather than as an adjunct to API supply.
It is a Good Manufacturing Practices guide written specifically for excipient manufacture. It addresses change control, contamination and cross contamination between grades, traceability through the supply chain, and the point at which general production becomes pharmaceutical production.
Excipients frequently reach buyers through distributors who repack, relabel or split lots, and each step is an opportunity for the chain of custody to break. The most serious historical excipient incidents involved substituted or mislabelled material moving through distribution.
TSE and BSE statements for animal derived materials, and GMO, allergen or vegetarian declarations where your market or product requires them.
Send the product or molecule, the grade, the quantity and the destination market. You will get a considered answer about what can be sourced and what documentation comes with it.