Chinese API maker Sichuan Pharmaceutical made two attempts, in responses sent in August and December 2010, to let the FDA know that it had resolved cross-contamination problems after a June inspection. But to no avail.
"Your firm has failed to conduct adequate assessment of the cross-contamination risks," the letter says. Those risks stemmed from making different APIs in adjacent workshops and from the company's failure to decontaminate and renovate a facility after it switched from making one API to another.
Warning Letter 320-11-019 demands detail: "In your response to this letter include your plans for decontamination, renovation, and reactivation (if appropriate) of your facility including the decontamination agent, decontamination plans, analytical methodology for environmental and product testing, and the data obtained to support the effectiveness of the decontamination plan."