- On May 21, 2026, FDA issued a final guidance for Industry: “Protein Efficiency Ratio (PER) Rat Bioassay Studies to Demonstrate That a New Infant Formula Supports the Quality Factor of Sufficient Biological Quality of Protein” for manufacturers of infant formula and laboratories conducting testing on infant formula.
- Under FDA’s Current Good Manufacturing Practices (CGMPs) for infant formulas, an infant formula must meet the quality factor of “sufficient biological quality of protein.” 21 CFR 106.96(e). This new final guidance seeks to help manufacturers design, conduct, and evaluate PER studies to meet this requirement. The guidance includes an overview of AOAC Official Method 960.48 and appropriate modifications thereto, as well as guidance on the development of protocols and reports and reference guidelines.
- A PER study in an animal model permits the determination of a formula’s protein quality and ensures that infants will not be fed a formula with inadequate or biologically unavailable protein.
- Keller and Heckman will continue to report on developments related to infant formula manufacturing.