Selected passages from the FDA letter
Quoted FDA text from the published dataset. These selected excerpts are not the complete letter.
Passage 1The methods provided showed differences from USP methods without justification and did not describe an internal standard, system suitability, and contained calculation errors.
Passage 2However, you did not provide adequate scientific justification to support that conclusion. Therefore, it is unclear whether you correctly identified the root cause and adequately expanded the investigation to include all impacted products and batches. In addition, your investigation did not include a review of your test methods, laboratory operations, and analytical results.
Citations in the original letter
As cited in this historical letter, not a statement of current regulatory requirements.
- 21 CFR 211.160
- 21 CFR 211.192