Five officials from a Chinese pharmaceutical company that sold a tainted antibiotic responsible for more than a dozen deaths have been sentenced to up to seven years in prison, the Associated Press reports, citing Chinese media.

The court convicted the five of being responsible for the deaths of 13 patients due to a lack of safety precautions in the drugmaker’s inspection process, the newspaper said. Among those convicted was the second-highest ranking exec at Qiqihar No. 2 Pharmaceutical.

The victims developed acute kidney failure at a hospital in the southern city of Guangzhou. Following the 2006 deaths, investigators found an unlicensed vendor had passed off a thickening agent used in antifreeze, diethylene glycol or DEG, which is also known as diglycol, as a substitute for an ingredient in the antibiotic used to treat liver and gallbladder diseases.

Quality inspectors at Qiqihar failed to discover the problem. The government shut down the drug company in 2006 and ordered its products removed from shelves. The antibiotic-linked deaths have drawn wide media attention and national outrage over the continued lack of enforcement of safety standards in China’s food and drug manufacturing sectors.