FDA's Warning Letter issued in April 2017 to a Chinese API manufacturer underlies an inspection performed in September 2016. This Warning Letter contains solely two points of criticism. Both concern sampling issues:
Firstly, the inspectors discovered that around 10% of the API batches manufactured between December 2014 and September 2016 exceeded the impurity limit set. Moreover, an additional 10% of batches yielded Out-of-Trend results.
The batches with the OOS results could be reprocessed but no effective corrective and preventive actions (CAPA) were implemented to correct process design and control flaws.
It was planned to monitor specific process parameters of the new batches' production with regard to the performance qualification of the process. Yet, the proposed parameters do not match with the "critical" process parameters monitored by the company in the last three years. Not all parameters were monitored which had been categorised as "critical and significant" in the youngest process qualification studies.
Secondly in the course of the inspection, the FDA complained about the sampling plan which was not based on scientifically-sound sampling practices.
The FDA inspector documented deficiencies in the sampling plan regarding the validation of the manufacture of an API.
Now, the company has to assess the adequacy of the sampling plans for all manufactured APIs. Moreover, the FDA is expecting a quality system about the improvements ensuring that all sampling performed by the company is representative and able to detect non-uniformity of the quality attributes that may vary within a batch.
For further information please access the complete FDA Warning Letter for Teva Pharmaceutical and Chemical (Hangzhou) Co. Ltd.