Step 1: Understanding the Question:
The question is about the standard minimum size fixed for a pilot batch relative to the batch that will eventually be manufactured commercially.
Step 2: Key Concept:
Process scale-up guidance requires the pilot batch to be large enough that its data can predict full-scale manufacturing behavior, and this is expressed as a fixed fraction of the production batch, not of a marketing batch.
Step 3: Detailed Explanation:
The accepted minimum is \(\frac{1}{10}\) of the intended production batch size, or ten thousand dosage units, whichever is greater. Using a smaller reference such as \(\frac{1}{5}\) would make the pilot batch too close to full scale to serve as a genuine intermediate step, and referencing a marketing batch instead of the production batch uses the wrong baseline entirely.
Step 4: Final Answer:
\(\frac{1}{10}\)th of the production batch.