The FDA sent a warning letter to Zhejiang Medicine Co. Ltd. referencing data and quality testing issues at its API facility in Xinchang, China. During an inspection at the plant more than a year ago, FDA investigators observed staff conducting multiple unofficial gas chromatography (GC) analyses of samples for residual solvents and recording the data in separate folders before conducting the officially reported sample analyses. The unofficial data, some of which showed large peaks, were not used to evaluate the quality of the API or to make batch release decisions. .