On November 12, 2025, the U.S. Food and Drug Administration (FDA) issued a Warning Letter (320-26-17) to Rhyz Analytical Labs, a contract testing laboratory located in Provo, Utah. The warning followed an FDA inspection conducted from June 2–5, 2025, during which significant violations of Current Good Manufacturing Practice (CGMP) requirements under 21 CFR Parts 210 and 211 were identified.
FDA concluded that, due to deficiencies in laboratory investigations and Quality Unit oversight, drug products tested by Rhyz Analytical Labs are considered adulterated within the meaning of Section 501(a)(2)(B) of the Federal Food, Drug, and Cosmetic Act (FD&C Act). While the firm provided a written response to the Form FDA 483 dated June 25, 2025, the FDA determined that the response was inadequate to address the identified systemic issues.
Key Non-Conformances Identified
The inspection and subsequent FDA Warning Letter highlighted several critical lapses in Rhyz Analytical Labs’ operations, summarized below as key non-conformances.
Non-Conformance 1: Inadequate Investigation of Invalidated OOS Microbiological Results
Regulatory Citation: 21 CFR 211.192
Rhyz Analytical Labs operates as a contract testing laboratory, performing chemical and microbiological testing of over-the-counter (OTC) drug products for its customers. FDA identified significant deficiencies in how the laboratory handled out-of-specification (OOS) microbial test results.
Specifically, the firm repeatedly attributed microbial excursions to “unknown laboratory error” or “contamination of an unknown source” without providing scientific justification to support these conclusions. In multiple investigations involving microbiological failures, the firm relied on generic corrective actions such as analyst retraining, without identifying or controlling the actual source of contamination.
FDA noted that this approach was repeated in at least five investigations, where the same conclusions and CAPA actions were accepted despite the absence of evidence supporting a laboratory error. In addition, the firm routinely relied on retesting to invalidate initial OOS results before adequately investigating potential contamination sources, which undermines the integrity of laboratory data.
The inspection further revealed that the firm did not assess the effectiveness of CAPA actions, nor did it trend laboratory errors or contamination events to identify recurring issues. FDA emphasized that well-documented, thorough, and scientifically sound investigations are necessary to determine root causes and to prevent recurrence.
While the firm acknowledged gaps in its procedures and the absence of a formal OOS handling system, FDA determined that the response failed to evaluate laboratory practices that could introduce microbial contamination or provide concrete actions to prevent recurrence.
Non-Conformance 2: Inadequate Quality Unit Oversight and Quality System
Regulatory Citation: 21 CFR 211.22(d)
FDA also found that Rhyz Analytical Labs failed to establish and maintain an adequate Quality Unit (QU) with defined responsibilities and authority over laboratory operations.
The Quality Unit did not exercise sufficient oversight of contract testing activities and failed to establish essential procedures governing critical operations. FDA specifically cited gaps in procedures related to Quality Unit responsibilities, deviation handling, change control, cleaning practices, and laboratory investigations.
In its response to FDA, the firm identified the absence of a quality management system as the root cause of these deficiencies and committed to creating the missing procedures. However, FDA concluded that this response was inadequate because it did not assess the potential impact of these systemic quality failures on previously generated test data reported to customers.
FDA further noted the lack of a comprehensive remediation plan to ensure that the Quality Unit would function effectively on an ongoing basis. The warning letter explicitly references the FDA’s guidance on Quality Systems Approach to Pharmaceutical CGMP Regulations, underscoring the expectation that contract testing laboratories implement risk-based, lifecycle quality systems equivalent to those used by manufacturers.
CAPA Plan Recommendations
Based on the FDA’s observations, the team at GMP Insiders recommends the following CAPA steps to restore compliance and establish a robust, science-driven quality system appropriate for a contract testing laboratory that would potentially find itself in a similar position:
Non-Conformance 1: Inadequate Investigation of Invalidated OOS Microbiological Results
Root Cause Analysis (RCA):
The recurring acceptance of unsupported “laboratory error” conclusions indicates the absence of a structured investigation framework tailored to microbiological testing. The laboratory relied on retesting as a justification mechanism rather than as a confirmatory step following root cause determination. Additionally, the lack of trending, contamination pathway analysis, and CAPA effectiveness checks reflects a reactive approach rather than a controlled laboratory system.
- Corrective and Preventive Actions (CAPA):
Establish and implement a formal OOS and laboratory investigation SOP aligned with FDA expectations, clearly defining phases of investigation, retesting criteria, and documentation requirements. - Conduct a retrospective, independent review of all invalidated microbiological OOS results for U.S. products over the last three years, classifying each result as confirmed laboratory error, true OOS, or inconclusive.
- Identify and document microbial contamination pathways related to sample handling, analyst technique, laboratory environment, equipment, consumables, and incubation practices.
- Introduce routine trend analysis for microbial excursions, invalidations, and investigation outcomes, with defined escalation thresholds.
- Define CAPA effectiveness verification criteria, such as recurrence rates and trend stabilization over time.
Related Article: How to Handle OOS Results in GMP Labs
Non-Conformance 2: Inadequate Quality Unit Oversight and Quality System
Root Cause Analysis (RCA):
The laboratory lacked a defined pharmaceutical quality system suitable for CGMP-regulated testing activities. The Quality Unit was not delegated, resourced, or structured to maintain oversight of laboratory operations, investigations, and data integrity. Responsibilities and authorities were not clearly defined or enforced.
- Corrective and Preventive Actions (CAPA):
Perform a comprehensive Quality Unit capability assessment covering organizational structure, independence, resources, training, and authority. - Design and implement a Quality Management System (QMS) aligned with FDA’s quality systems guidance, adapted specifically for a contract laboratory environment.
- Develop and implement procedures governing:
- Quality Unit responsibilities and approvals
- Deviations and laboratory incidents
- Change control
- Cleaning and sanitation practices
- Laboratory investigations and data review
- Ensure the Quality Unit has final authority over investigation conclusions, data invalidations, client reporting, and method changes.
- Establish routine management review meetings to evaluate quality performance metrics, including OOS rates, invalidations, deviations, and audit outcomes.
Timeline for Implementation
Immediate Actions (0–3 Months):
- Implement core SOPs for OOS handling, investigations, and deviation management.
- Reinforce Quality Unit authority over all laboratory investigations and data reporting.
- Initiate the retrospective review of invalidated microbiological OOS results.
Short-Term Actions (3–6 Months):
- Complete the retrospective OOS analysis and assess potential impact on data reported to customers.
- Deploy QMS elements across laboratory operations, including change control and cleaning procedures.
- Begin routine trending and review of laboratory quality performance indicators.
Long-Term Actions (6–12 Months):
- Integrate quality metrics into a formal management review process.
- Conduct internal audits to verify the effectiveness of the QMS and Quality Unit oversight.
- Continuously refine procedures and resourcing based on audit results and inspection readiness assessments.
Conclusion
The FDA Warning Letter issued to Rhyz Analytical Labs highlights how contract testing laboratories remain fully accountable under CGMP, particularly when their data supports release and lifecycle decisions for marketed drug products. Repeated acceptance of unsupported laboratory error conclusions and the absence of an empowered Quality Unit undermined the reliability of microbiological test results generated for clients.
This case highlights the need for contract laboratories to implement structured investigation systems, meaningful CAPA effectiveness checks, and a robust quality management framework. Addressing these deficiencies promptly and comprehensively will be essential for restoring regulatory confidence and ensuring the integrity of laboratory data relied upon across the pharmaceutical supply chain.
