FDA Identifies Critical Deficiencies in Analytical Testing and CGMP Oversight

On 06 October 2026, the U.S. Food and Drug Administration (FDA) published a new Warning Letter dated 02 September 2026. In the letter, the FDA described significant violations of current good manufacturing practice requirements identified during an inspection conducted from 09 to 13 March 2026 at a drug manufacturing facility in Taiwan.

The FDA concluded that the methods, facilities and controls used for manufacturing, processing, packing and holding drug products did not conform to CGMP requirements under 21 CFR Parts 210 and 211. The company’s response to the Form FDA 483 was considered inadequate because it did not provide sufficient supporting documentation or evidence that effective corrective actions had been implemented.

Inadequate Analytical Testing Before Batch Release

One prominent deficiency concerned the laboratory control system and the release of finished drug products.

The facility had released and distributed OTC drug products without performing all required tests. In one example, assay testing of the active pharmaceutical ingredient was not included in finished product release testing.

The FDA also found that the quality system did not ensure that all required tests were identified, documented and performed. In addition, there was no adequate written procedure or quality agreement clearly defining the responsibilities of the contract manufacturer and the customer for:

• Establishing product specifications
• Performing and reviewing analytical testing
• Investigating deviations and failures
• Releasing and disposing of batches
• Communicating quality-related information

The FDA requested a comprehensive quality agreement and complete lists of the chemical and microbiological methods and specifications used for each product before batch disposition.

Deficiencies in Incoming Material Testing and Supplier Qualification

The facility did not perform all required identity and conformity testing on incoming APIs and other components before use in manufacturing. Instead, it relied extensively on supplier certificates of analysis without adequately establishing the reliability of the suppliers’ analytical results.

The FDA specifically referred to missing tests required by applicable USP monographs, including identity testing and tests for impurities, heavy metals, residue on ignition, alkalinity, organic impurities and other relevant quality attributes.

The Warning Letter stresses that reliance on a supplier’s certificate of analysis is only acceptable when the manufacturer has appropriately qualified the supplier’s analytical results and verifies their reliability at suitable intervals. A certificate of analysis does not replace the manufacturer’s responsibility to ensure that components meet requirements for identity, strength, quality and purity.

Inadequate Process Validation and Pharmaceutical Water Control

The facility had not adequately validated the manufacturing processes for its OTC drug products. In particular, the validation documentation did not correspond to the actual manufacturing process. A manufacturing step included in the validation documentation was absent from the relevant batch record, while separate products with different processes were supported by the same validation.

The FDA also identified deficiencies in the qualification and monitoring of a pharmaceutical water system. The qualification protocol and report did not include critical parameters such as:

• Total organic carbon
• Conductivity
• Microbial content

The FDA noted that increasing sampling frequency alone is not sufficient if appropriate limits and scientifically justified monitoring requirements have not been established.

Quality Unit Oversight and Change Control Failures

The quality unit (QU) did not exercise adequate oversight of manufacturing operations. Manufacturing process parameters were changed without documented justification and without following the established change management and abnormal situation procedures.

The FDA requested a comprehensive assessment and remediation plan to ensure that the quality unit has the authority, resources and procedures required to oversee manufacturing effectively. This includes complete batch review before disposition, approval of process changes before commercial manufacture and appropriate oversight of investigations and CAPA activities.

Manufacturing Activities Suspended

During the inspection, the facility stated that its FDA drug registration had been allowed to expire and that it would only be renewed if a U.S. order was received.

The FDA stated that the facility must notify the Agency before resuming regulated manufacturing operations. Before doing so, the company is expected to resolve the identified deficiencies and systemic weaknesses.

For further information, please see the complete Warning Letter concerning TCI Co., Ltd BioCosme PABP BRANCH, published on the FDA’s website.