The FDA has issued a warning letter to Wyeth Pharmaceuticals citing current good manufacturing practice (cGMP) violations ranging from impurities in drugs to improper cleaning of packing machines at its Guayama, Puerto Rico, facility.

The letter, sent May 8 and posted on the FDA's website May 30, follows up on an inspection conducted between Nov. 7 and Dec. 15, 2005. It notes that the facility was not only outside of cGMP regulations but also failed to comply with new drug application -- field alert reporting requirements by sending out notices five months late. Inadequate efforts to correct the identified errors were also noted.

In one case, the letter states, Wyeth made no effort to identify the cause of an impurity until the issue was raised in the inspection, which "raises serious concerns regarding the timeliness of your investigations." The letter points out that although the investigation had been going on for several months, the affected drug, Triphasil 21 and 28 tablets, remained in the market. However, since the date the letter was sent Wyeth has recalled the product at the wholesale level, according to company spokesman Doug Petkus.

Maintenance of the facility's packaging equipment was also questioned by the FDA, with a "screw and two washers" found in one shipped bottle and "ejector pins from the filling/packaging line" found in another. The letter goes on to point out the neither the "cleaning procedures nor the line clearance inspections were able to detect that the affected equipment was missing some of its parts." Other instances cited by the letter include drugs not being cleaned out of the filler machines.