The State Food and Drug Administration (SFDA) has said that while it does enforce its own strict controls on the chemicals used in pharmaceuticals, "safeguarding the legality, quality and safety of active pharmaceutical ingredients (APIs)" is ultimately the responsibility of the importing country.

According to the SFDA, companies that manufacture APIs in China must be registered and certified as pharmaceutical companies by the watchdog after it carries out an inspection of the facility. It is this authority that importing firms and the regulatory agencies of importing countries should look for before accepting any product from a Chinese company.

In addition, any importing country should also still conduct their own stringent quality control tests on APIs, excipients and finished drugs, the agency said.

Where it gets into a grey area is if a company is registered as a chemical manufacturer and not a pharmaceutical company, but still supplies chemicals to the pharmaceutical industry, as is believed to be not uncommon. In this case, the manufacturer is not subject to SFDA inspection and approval.

This was in fact the case with the Chinese supplier of the API for Baxter's heparin that was recently recalled form the market after a safety scare. This plant is now part of an investigation into the cause of the defective product - The SFDA has confirmed that the Chinese company involved was listed as a chemicals company and not a pharmaceutical company and was not registered with the agency as a heparin supplier.

Baxter has suspended the production of its blood-thinning drug heparin in multi-dose vials, following the deaths of four patients in the US who were given the drug in high doses, along with 350 reports of severe allergic reactions to the drug, with symptoms including a rapid drop in blood pressure, burning sensations, headaches, throat swelling and a shortness of breath.

It later emerged that it has emerged that the US Food and Drug Administration (FDA) has never inspected the facility in China where some of the API was sourced. The US watchdog has now said that that a team of inspectors is on its way to China to take a look at the plant in question and assess whether it may have played a role in causing the heparin side effects.

The identity of the Chinese plant in question has now been revealed as Changzhou SPL, a factory in the city of the same name. This facility is actually 55 per cent owned by Scientific Protein Laboratories, the company that also supplies the heparin API from a site in Wisconsin, US.

The FDA is conducting an investigation at both of these plants, as well as a facility owned by one of Baxter's subsidiaries in New Jersey, where the finished heparin is packaged.

The SFDA also indicated that it was assisting the FDA with its enquiries and was also conducting its own inspection of the Chinese site.