UPDATE 4-FDA warns P&G over vitamin C in DayQuil and NyQuil

* Says combination products do not follow FDA rules

* P&G says will work with FDA to resolve concern

* P&G shares end session up 0.1 pct after falling 0.4 pct

* FDA says letter made public “in error” (Adds FDA comments, removal of letter from website)

By Jessica Wohl and Susan Heavey

CHICAGO/WASHINGTON, Oct 14 (Reuters) - The U.S. Food and Drug Administration warned Procter & Gamble Co PG.N on Wednesday that its Vicks DayQuil and NyQuil products with vitamin C have false and misleading labeling, and P&G said it would work with the agency to resolve its concerns.

The FDA’s list of approved ingredients for over-the-counter cold-cough drug products does not allow for a combination of vitamin C with the other active ingredients in the two products, the agency said in a warning letter.

The FDA also said that the products are misbranded because vitamin C is included in the list of inactive ingredients.

“Because the vitamin C in these products is an active drug ingredient, it is therefore both false and misleading to state that it is an inactive ingredient in these drug products,” the FDA wrote to P&G President and Chief Executive Bob McDonald.

The FDA, which initially posted the letter on its website at, later removed it.

FDA spokesman Christopher Kelly did not deny the agency’s letter but told Reuters: “The warning letter was posted in error. We have no further comment at this time.”

P&G advertises that DayQuil Plus Vitamin C contains more than 150 percent of the recommended value of vitamin C.

The company issued a statement saying it believes it is “marketing within the FDA regulations and will work with the FDA to resolve the concern together.” The FDA letter asked for a response from the company within 15 working days.

The FDA said that listing vitamin C as an inactive ingredient, but also listing it as a dietary ingredient in the “Supplement Facts” section of the products’ packaging, was misleading and likely to confuse consumers.

P&G said that its marketing clearly differentiates the benefits provided by the products’ active ingredients versus the dietary supplement vitamin C.

The action comes just weeks after U.S. antitrust regulators approved P&G's plan to sell its pharmaceuticals business to Ireland's Warner Chilcott Plc WCRX.O for $3.1 billion. Vicks products, which are sold over the counter and do not need prescriptions, are not included in that sale.

The FDA has taken similar action with other products. Last October, the agency said that two over-the-counter Bayer AG BAYGn.DE aspirin products that contain dietary supplements have not been proven to work and were being sold illegally.

The FDA stopped short of calling for those pain relievers, Bayer Aspirin with Heart Advantage and Bayer Women’s Low Dose Aspirin + Calcium, to be removed from store shelves. [ID:nN28388648]

Shares of P&G, which fell to a session low of $57.04 after the letter was released, ended Thursday’s trading session up 5 cents at $57.31. (Reporting by Jessica Wohl in Chicago and Susan Heavey in Washington; Editing by Tim Dobbyn, Gary Hill and Bernard Orr)