FDA Warning Letter Lessons for Aseptic Processing: Smoke Studies, Media Fills & CAPA Evidence

1. Why This FDA Warning Letter Matters

On September 18, 2026, the U.S. Food and Drug Administration (FDA) issued a Warning Letter to Empower Clinic Services, LLC dba Empower Pharmacy following an inspection conducted from November 3 through November 14, 2025. FDA had issued a Form FDA 483 at the conclusion of that inspection.

The Warning Letter provides valuable lessons for organizations involved in sterile compounding and aseptic processing. Among the concerns described by FDA were inadequate smoke studies under dynamic conditions, media fills that did not represent sufficiently challenging conditions, deficiencies in environmental monitoring and aseptic controls, and weaknesses in the documentation used to demonstrate corrective actions.

The case reinforces an important principle for sterile operations: successful results alone are not enough. The facility must be able to demonstrate, through complete and traceable evidence, that the aseptic process remains in a state of control.

2. Dynamic Smoke Studies: Demonstrating Protection of the Critical Zone

FDA stated that the firm failed to perform adequate smoke studies under dynamic conditions to demonstrate unidirectional airflow within the ISO 5 area.

Airflow visualization studies are an important component of contamination-control assurance because they provide visual evidence of how air moves around critical processing locations.

A smoke study should not merely demonstrate acceptable airflow in an empty or relatively undisturbed environment. The study should represent the conditions that occur during actual aseptic operations.

A robust dynamic airflow visualization study should consider:

• Normal operator positioning and movement.
• Representative aseptic manipulations.
• Routine and non-routine interventions.
• Equipment configuration during production.
• Material transfers into and out of critical areas.
• Potential airflow disturbances caused by personnel or equipment.
• Protection of exposed sterile product and critical surfaces.

The fundamental question is not simply, “Was a smoke study performed?”

The more meaningful question is: “Does the study demonstrate that critical locations remain adequately protected during representative operating conditions?”

3. Media Fills Must Challenge the Aseptic Process

FDA also stated that the firm's media fills were not performed under the most challenging or stressful conditions. FDA therefore concluded that there was inadequate assurance that the facility could aseptically produce drug products.

This distinction is important.

A media fill is not simply an exercise in which growth medium is processed and the final units show no microbial growth. It is an aseptic process simulation intended to provide evidence that the manufacturing process can maintain sterility when challenged under representative operating conditions.

The design of a media fill should therefore consider scientifically justified worst-case conditions, including where applicable:

• Maximum or appropriately challenging operating duration.
• Representative number of operators.
• Routine aseptic interventions.
• Non-routine but permitted interventions.
• Equipment adjustments and manipulations.
• Material transfers.
• Representative container and closure configurations.
• Shift changes or personnel changes where applicable.
• Other conditions capable of challenging aseptic process control.

A passing media fill does not automatically mean that the aseptic process has been adequately simulated. The design of the simulation is as important as the final result.

4. Media-Fill Reconciliation and Data Traceability

One of the most instructive aspects of the Warning Letter concerns the documentation supporting a January 2026 media fill.

The firm's summary reportedly concluded that the incubated vials showed no contamination. However, FDA identified gaps and discrepancies between the summary and the underlying media-fill records.

FDA questioned whether all units could be adequately accounted for and inspected based on the documentation provided. The agency also identified unexplained record designations and discrepancies concerning the number of units represented in the records.

This demonstrates why media-fill reconciliation is a critical part of the simulation.

A defensible media-fill package should provide clear traceability for:

• Units filled.
• Units rejected before incubation and the justification.
• Units incubated.
• Units inspected after incubation.
• Damaged or missing units.
• Positive units, if any.
• Reconciliation of the final unit count.

The final report should be fully supported by the underlying raw data.

5. Data Transcription Requires a Clear Audit Trail

FDA also noted that multiple media-fill records had been transcribed onto a newer form because the original results had been documented on the wrong form.

FDA explained that transcription of original data, even when performed for legitimate administrative reasons, must be carefully controlled, documented, and justified.

This is an important data-integrity lesson.

When GMP data are transferred or transcribed, the organization should maintain clear traceability to the original record and document:

• Why the transcription was necessary.
• Who performed the transcription.
• Who reviewed or authorized it.
• When it occurred.
• How the transcribed information was verified against the original data.
• How the original record remains preserved and retrievable.

The objective is to maintain a transparent audit trail so that an independent reviewer can reconstruct what occurred.

6. CAPA Requires Evidence, Not Only Commitments

The Warning Letter also provides an important lesson about responding to regulatory observations.

The firm reported that an additional smoke study had been executed in March and April 2026. However, FDA stated that it could not fully evaluate the corrective action because the study remained under post-execution review and a final formal summary report had not been provided.

This illustrates the difference between describing a corrective action and demonstrating that the corrective action has been effectively implemented.

A strong CAPA package should progressively demonstrate:

• Commitment: What the organization intends to correct.
• Implementation: Evidence that the corrective action has been approved and implemented.
• Execution: Records demonstrating that the revised process or study was actually performed.
• Evaluation: Documented review of the results.
• Effectiveness: Evidence demonstrating that the action addressed the identified problem and reduced the risk of recurrence.

Regulators need objective evidence to evaluate whether a remediation activity has actually restored control.

7. Quality Oversight Extends Beyond One Observation

The Warning Letter described concerns extending beyond smoke studies and media fills. FDA also cited issues involving equipment used to control aseptic conditions, written procedures intended to prevent microbiological contamination, Quality Unit responsibilities, environmental monitoring, and production and process controls.

This is an important reminder that aseptic-processing deficiencies should not always be treated as isolated procedural failures.

For example, an inadequate smoke study may indicate broader weaknesses involving:

• Facility and equipment qualification.
• Contamination-control strategy.
• Aseptic-process design.
• Personnel qualification.
• Environmental monitoring.
• Deviation and investigation systems.
• Change control.
• Quality oversight.

Quality management should therefore evaluate whether an observation represents a localized deficiency or evidence of a broader systemic weakness.

8. Practical Inspection-Readiness Checklist

Sterile manufacturing and compounding facilities can use the lessons from this case to evaluate their own inspection readiness.

Airflow Visualization

• Are smoke studies current and formally approved?
• Do they represent dynamic operating conditions?
• Are routine and significant interventions represented?
• Can critical airflow patterns be clearly evaluated from the recordings?

Media Fills

• Are worst-case conditions scientifically justified?
• Are representative interventions incorporated?
• Are all filled, rejected, incubated, inspected and discarded units reconciled?
• Does the final report agree with the underlying records?

Data Integrity

• Are original records preserved?
• Are corrections and transcriptions attributable and traceable?
• Can reviewers reconstruct the activity from the records?

CAPA

• Is the root cause adequately supported?
• Are corrective and preventive actions clearly defined?
• Is implementation supported by objective evidence?
• Are effectiveness checks predefined and documented?

Quality Oversight

• Does the Quality Unit independently review aseptic-processing controls?
• Are recurring trends evaluated across deviations, environmental monitoring and process simulations?
• Are significant deficiencies escalated appropriately to management?

9. Management Takeaway: Build the Evidence Before the Investigator Arrives

One of the strongest lessons from this FDA action is that regulatory compliance depends not only on performing the correct activities, but also on maintaining evidence capable of demonstrating that those activities were properly designed, executed, reviewed and found effective.

For aseptic operations, management should periodically challenge the organization with a simple question:

“If an FDA investigator requested the complete evidence package today, could we demonstrate that our aseptic process remains in a validated and controlled state?”

If smoke studies, media fills, environmental-monitoring records, investigations, CAPAs and qualification records cannot collectively answer that question, the organization may have an inspection-readiness gap.

10. Conclusion

The September 2026 FDA Warning Letter provides valuable lessons extending well beyond a single facility.

For organizations performing sterile compounding or aseptic manufacturing, the key principles are clear: airflow visualization should represent dynamic operations; media fills should meaningfully challenge the aseptic process; all units and records should be fully traceable; data transcription requires appropriate controls; and CAPA effectiveness should be demonstrated through objective evidence.

Most importantly, Quality oversight should connect these activities into an integrated system for maintaining contamination control and sterility assurance.

Regulatory note: This article summarizes and interprets publicly available FDA information for educational purposes. The observations discussed are attributed to FDA. Readers should review the complete FDA Warning Letter and applicable regulatory requirements when evaluating their own operations.