The NIH Clinical Center has a pharmaceutical unit that makes drugs for clinical research studies. (Michael Reynolds/EPA)

The National Institutes of Health has suspended operations of a pharmaceutical unit that makes drugs for clinical research after two vials of a product being used in an experimental study were found to have fungal contamination, officials said Thursday.

Vials made from the same batch were given to six patients, who were notified and being monitored. None has developed signs of infection or illness. The vials of albumin, a protein in blood, were being used to administer the drug interleukin, which may be used to battle some forms of cancer.

Another 250 participants in 43 studies who are currently receiving or scheduled to receive products made by the unit could also be affected. NIH has notified the principal scientists responsible for each of those studies, and is in the process of notifying the participants. The vast majority are not immediately due for treatment and NIH is trying to obtain alternative sources for the products. To date, officials have found no evidence of patient harm.

The contamination was discovered in April after a complaint was made to the Food and Drug Administration. The FDA inspected the unit between May 19 and May 29 and found a series of deficiencies.

“This is a distressing and unacceptable situation,” said NIH Director Francis S. Collins in a statement. “The fact that patients may have been put in harm’s way because of a failure to follow standard operating procedures ... is deeply troubling. I will personally oversee the steps to protect the safety of patients and remedy the situation as swiftly as possible.”

Among the problems the FDA identified in their inspection were flaws in the air handling system, deficient systems to clean and disinfect equipment, and lack of compliance with standard operating procedures.

The vials were contaminated with two types of fungi, aspergillus, the most common cause of fatal fungal infections, and a non-human pathogen.

“Both are equally worrisome. Neither should be found in sterile vials,” said Larry Tabak, NIH’s principal deputy director. “It is conceivable that these deficiencies led to the spore contamination in these two vials.”

The safety lapses cited by the FDA inspections included: No filter or screen covering a vent into a laboratory “clean room.” Insufficient documentation about the cleaning of the facility. Insects found in a pair of ceiling light bays in clean rooms. Employees not wearing protective apparel. A water system that could harbor “microbial proliferation.”

Inspectors found that the facilities themselves were “not designed and controlled to prevent contamination risks to sterile drugs.”

The Pharmaceutical Development Section makes about 100 products a year for a range or diseases, from rare disorders to different types of cancers. It is supposed to operate under the same stringent manufacturing standards as a drug company. It formulates raw materials into tablets, eye drops, nose sprays and sterile injections.

“These are packaged in many instances dose by dose so there could be many, many individual doses, and the numbers could be quite high,” Tabak said.

The contaminated vials were part of a batch of 640 vials. None of the other vials showed visible contamination. All the products made in the section have been sent to outside labs for testing. Those results could take weeks.