A plant operated by US drugmaker Wyeth has fallen foul of Food and Drug Administration (FDA) inspectors, forcing it to recall some product batches.

The facility, located in Puerto Rico, is involved in the manufacture of a number of Wyeth’s products, including antidepressant Effexor (venlafaxine), hormone replacement therapy Prempro (conjugated oestrogens and progestin) oral contraceptive Triphasil (levonorgestrel and ethinyloestradiol) and painkiller Advil (ibuprofen).

Batches of Triphasil have already been recalled, and the company is working with the agency to try to resolve the issues, according to Wyeth, although it stressed the findings suggested no medical risk to patients.

However, analyst Richard Evans of Sanford C Benstein believes the violations could hold up approval of Wyeth’s new antidepressant desvenlafaxine, according to a report in the Wall Street Journal.

Desvenlafaxine, a follow-up to its blockbuster Effexor range which is facing patent expiry later this year, is an important near-term pipeline product for Wyeth, and the company is hoping to launch it as soon as possible to allow it to migrate Effexor patients to the new drug ahead of generic competition.

Among the violations detailed by the FDA in a warning letter include a failure to clean and maintain packaging equipment to prevent contamination, poor inspection procedures and failure to investigate incidents of contamination.