CAPA and Root Cause Analysis - why FDA keeps calling them out

FDA's expectations are consistent and pragmatic: investigations must be thorough, well-documented, scientifically sound, and timely, and they must translate into CAPA that is appropriately scoped and effective. The two April 2026 Warning Letters illustrate what happens when that chain breaks.
The Warning Letters were issued to Active Cosmetics Manufacturing Inc., a manufacturer of topical over-the-counter (OTC) drug products, and CareFusion 213, LLC, a manufacturer of sterile drug products.

Lessons learned from the Warning Letters:

Lesson 1: Retesting is not an investigation (Active Cosmetics)
In the Active Cosmetics letter, FDA highlighted release decisions made after OOS microbiological results were followed by passing retests, "without a thorough investigation to determine the cause of the original result". FDA reiterates a core principle: "Passing retest results alone cannot serve as the basis for invalidating OOS results".

From a CAPA/RCA perspective, this is a classic failure mode:

• RCA failure: the organisation did not perform a systemic investigation into root cause of microbial OOS results.
• CAPA failure: without understanding whether the issue arose from laboratory controls, method limitations, process variability, raw materials, equipment/facilities, or contamination routes, any corrective action will be incomplete and preventive actions will be speculative.
• Scope/risk failure: FDA also called out the absence of a "comprehensive drug product impact assessment" covering potentially affected products.

FDA's requested remediation is telling: independent, retrospective reviews of invalidated OOS, stronger investigation competencies, better root cause evaluation, CAPA effectiveness, and stronger Quality Unit oversight. In other words, the regulator is not asking for "a better form"; they are asking for a "better system".

Lesson 2: A "probable cause" without evidence produces ineffective CAPAs
CareFusion faced a high-volume, multi-symptom complaint landscape (foreign matter, missing components, compromised seals) and FDA found that investigations repeatedly lacked thoroughness, adequate root cause identification, scientific rationale and extension to other potentially affected batches-thereby making CAPA ineffective.

FDA provides concrete examples. One investigation attributed black specks/possible mould to inadvertent particulate introduction from the environment, but "did not extend" to other lots made under the same conditions or on the same equipment, and did not sufficiently examine facility/equipment cleaning/maintenance and personnel practices. Another complaint investigation proposed "equipment vibrations" as the probable root cause for broken/missing components, but again "did not extend" to other batches and did not address other elements of the complaint (e.g., illegible printing). These are hallmark indicators of "fragmented RCA": treating each complaint as a one-off, rather than as potential evidence of a "systemic defect pattern".

FDA's critique goes further: procedural updates and training, by themselves, "do not address systemic failures" when Quality Unit oversight allowed deficient investigations to persist. And FDA notes the firm only performed extended investigation work "after FDA identified gaps", without explaining why the investigation wasn't initially broadened when systemic packaging-material issues were evident.