Bulk

A large quantity of drug substance or drug product intermediate held before the next step, such as final filling and packaging. For biologics, Japanese documents also speak of purified bulk (精製バルク). Bulk is often held in tanks or bags while the next step is prepared, so the allowed hold time must be supported by data showing no microbial growth or degradation. Shipping bulk to another site, for example to a fill-finish partner in Japan, adds shipping validation and stability data under transport conditions.