A heavily staffed FDA inspection of pharmaceutical giant Mylan’s manufacturing facility in Morgantown, West Virginia netted the company a lengthy Form 483 listing numerous deficiencies in the firm’s quality control unit.

The inspection was handled by a team of eight agency officials, including four investigators. The 483 included 13 observations ranging from inadequate process controls to failure to review changes to written procedures.

The investigators found that the firm’s quality unit sometimes failed to properly oversee certain tasks. The unit was not always involved in approving change controls for products and it did not adequately conduct reviews and approvals of equipment used in manufacturing, packaging, labeling and holding drug products.

The quality unit also failed to adequately validate cleaning methods for all manufacturing equipment shared between its 230 oral dosage drug products, risking cross-contamination of active ingredients and detergent between the products. In addition, a tour of the manufacturing area revealed an unknown crystal-like yellow residue on a piece of equipment’s product support screen.

The investigators found that the firm repeated laboratory analyses for cleaning verification tests until it achieved passing results. A review of swab sample analysis for Divalproex Sodium ER tablets found multiple instances of parts of equipment units being re-cleaned and re-swabbed until passing results were obtained.

Mylan said in a statement that it “submitted a comprehensive response to the agency and committed to a robust improvement plan” following the inspection.

“We remain confident in the quality, safety and efficacy of our drug products, including those in distribution, and we continue to manufacture and ship product from the site,” the company said, adding that it is “fully committed to working with FDA to address its observations.”