Senator Sherrod Brown (Democrat -Ohio) is particularly concerned about cases where elements of production have been outsourced to overseas companies, noting: " In recent testimony to the Senate Committee on Health, Education, Labor, and Pensions (HELP), an FDA official acknowledged that American drug companies outsource operations to take advantage of weak drug safety standards abroad ."
The letters come against a backdrop of rising concern in the US about the safety of medicines, in no small part because of the ongoing saga about contaminated heparin products.
Several countries around the world have recalled heparin products after discovering they contained contaminated heparin sourced from a supplier in China.
That event in turn precipitated an administration request for increased funding for the FDA to ensure import safety.
Brown's open letter to Janet Woodcock - director of the FDA's Center for Drug Evaluation and Research (CDER) - asks the agency to evaluate its safeguards for protecting US consumers from " drug products containing tainted, outsourced ingredients. "
The letter, which can be found here , also expresses concern that the world's largest drugmaker Pfizer outsources 17 per cent of its active pharmaceutical ingredient (API) production.
Brown has also sent a separate letter to Gerald Migliaccio, a vice present at Pfizer responsible for outsourcing strategy, asking for information on how much Pfizer saves each year from outsourcing as well as on the frequency and nature of its outsourcing to countries with less stringent drug oversight standards.
" It is no coincidence that drug ingredients produced in countries with weak safety standards are often contaminated ," said Brown. "
The FDA must immediately review pharmaceutical outsourcing and make necessary changes to keep American consumers safe ."
Among the information requested of Woodcock in the letter are the volume of pharmaceutical ingredients outsourced by US drug manufacturers to China and other countries with weaker drug safety regimes than that of the US, and the expected incremental annual cost of protecting the public from tainted pharmaceutical ingredients produced in those countries.
The FDA is already embarking on measures to look at this issue.
For example, it recently joined with regulatory bodies in Europe, Canada and Australia to launch a pilot project for joint inspections of overseas API manufacturing plants.
Draft legislation has also been proposed - the FDA Globalisation Act of 2008 - which would require the FDA to inspect foreign manufacturing plants every four years.
But there are those who feel that it is nonsense to expect the FDA to regulate the world in this fashion.
Writing in the New England Journal of Medicine earlier this month, Jerry Avorn, a professor of medicine at Harvard Medical School, notes: " It would be wrong to view the heparin debacle as primarily an FDA failure ."
" The FDA's budget for surveillance of foreign drug manufacturers is an order of magnitude or two too small ," according to Avorn.
At current funding levels, it would take the FDA more than 13 years to inspect all foreign plants exporting prescription drugs to the US and 27 years to inspect all foreign plants exporting medical devices, he points out.
" Criticising the FDA for failing to stay on top of such inspections when it doesn't have the requisite funds is victim blaming, not policy analysis ," comments Avorn.