Glossary
Yield (Theoretical / Actual)
Theoretical yield is the quantity that would be produced with no loss, actual yield is what was produced; where the percentage of the two falls outside the set range it must be investigated.
Details
21 CFR 210.3(b) defines theoretical yield as the quantity that would be produced at any appropriate phase of production based on the quantity of components to be used, in the absence of any loss or error, actual yield as the quantity actually produced, and percentage of theoretical yield as the ratio of actual to theoretical yield at the same phase, expressed as a percentage; the ICH Q7 glossary carries the same sense of theoretical yield. 211.103 requires actual yields and percentages of theoretical yield to be determined at the conclusion of each appropriate phase of manufacturing, processing, packaging, and holding, with the calculation performed by one person and independently verified by a second (one person where automated equipment is used); 211.186(b)(7) requires the master record to state the upper and lower percentage limits beyond which investigation is required; 211.192 requires any batch outside that range to be thoroughly investigated even if it has already been distributed; and EU GMP Chapter 5 §5.8 likewise requires yield checks as necessary. If reconciliation compares whether the count of materials and labelling adds up, yield measures how much came out of the process. Inspections cite yield limits never set, excursions approved without investigation, and calculations with no independent verification signature.
Related sections
Related terms
Real inspection findings
Findings from regulators' inspection documents in which this term appears.
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The information provided did not demonstrate that your manufacturing processes are reproducible and controlled to yield a product of uniform character and quality.
FDA · FDA Warning Letter · 2024-11-26 -
Based on the information you provided, you did not demonstrate that your manufacturing processes are reproducible and controlled to yield a product of uniform character and quality.
FDA · FDA Warning Letter · 2023-01-03 -
The batch records you provided in response to our request for records lacked adequate production details, including, but not limited to: Sampling information Actual and theoretical yield calculations Identification and…
FDA · FDA Warning Letter · 2024-04-02
