A congressional panel is opening an investigation into McNeil Consumer Healthcare’s recent recall of children’s over-the-counter medicines.

The House Committee on Oversight and Government Reform is investigating conflicting accounts of what prompted the recall, as well as McNeil’s handling of consumer complaints. It wants to look at a chronology of events leading up to the recall, as well investigation reports from both McNeil and the Food & Drug Administration (FDA). It also plans to ask the FDA for its procedures governing routine inspections of over-the-counter drug makers and recalls.

McNeil – a unit of Johnson & Johnson – said it plans to cooperate with the committee’s investigation.

McNeil issued the recall last Friday, saying some drugs might contain a higher concentration of active ingredient than is specified; others may contain inactive ingredients that may not meet internal testing requirements; and others may contain tiny particles. The medications – 43 varieties of Tylenol Infant Drops, Children’s Tylenol Suspensions, Children’s Tylenol Plus Suspensions, Motrin Infant Drops, Children’s Motrin Suspensions, Children’s Zyrtec Liquid in Bottles, and Children’s Benadryl Allergy Liquid in Bottles – were recalled in the U.S. and 11 other countries.

Yesterday, we reported that the Food & Drug Administration (FDA) cited deficiencies at the company’s Fort Washington, PA facility that could have caused bacterial contamination of raw materials in the recalled products. The agency also charged that McNeil knowingly used bacteria-contaminated materials to make the recalled drugs. The agency also faulted McNeil for failing to initiate corrective action after receiving 46 consumer complaints from June 2009 to April 2010 regarding foreign materials in the drugs.

Earlier, the company said it is making all efforts to correct the problems and has shut down production of 50 over-the-counter medications made at the facility.