FDA Warning Letter: Violations of GMP Fundamentals in Quality Control and Manufacturing Process

On March 13, 2020, the Chinese contract manufacturer for OTC products, Hangzhou Linkeweier Daily Chemicals Co. Ltd. received a Warning Letter. This letter describes a series of fundamental GMP deficiencies which show that the company has neither quality control of the starting materials and finished products nor its manufacturing process under control. As a result, the company is found to have a completely inadequate quality assurance system ("Your firm's quality systems are inadequate.").

During their visit at the site in November 2019, inspectors identified GMP violations in the following areas:

Quality control of the final product

Neither the finished products nor the production equipment are tested for microorganisms. There is no control over microbial contamination of the products and the production environment and no risk assessment for this.

Incoming material testing

There is no control of the raw materials and starting materials for compliance with the specifications; rather, those responsible for quality control rely on the certificates of the suppliers without checking the values and analytical methods stated.

In-process controls

The manufacturing processes are not validated. There are no written procedural instructions neither for these processes nor for in-process controls. Also, a continuous monitoring programme to ensure that the manufacturing process is stable and delivers consistent product quality could not be presented to the inspectors.

Stability testing

There is no programme for testing chemical and microbiological stability. Therefore, the company cannot guarantee that its products will meet the defined specifications and quality features within the term of the contract.

On 9 March 2020, the company was placed on Import Alert.

Please also see the FDA's Warning Letter to Hangzhou Linkeweier Daily Chemicals Co. Ltd.

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