Story highlights Excedrin and Bufferin products are part of the voluntary recall

Novartis says "stray" pills "from other Novartis products" put in the wrong package

An internal probe also found evidence of "broken gelcaps (and) chipped tablets"

The recall and processing upgrades will cost $120 million, Novartis estimates

Pharmaceutical company Novartis on Sunday voluntarily recalled a number of over-the-counter drugs -- including certain bottles of Excedrin and Bufferin -- because of complaints about mislabeled and broken pills.

The Switzerland-based company said on its website that "there have been no related adverse (health) events" related to the problems. At the same time, it urged U.S. consumers to "either destroy or return unused" products that are part of the recall.

The items involved in the voluntary recall include Excedrin and NoDoz products with expiration dates of December 20, 2014, or earlier, as well as Bufferin and Gas-X Prevention products with December 20, 2013, or earlier expiration dates.

"(Novartis) is taking this action as a precautionary measure, because the products may contain stray tablets, capsules or caplets from other Novartis products, or contain broken or chipped pills," the company said.

The moves follows Novartis' decision to suspend operations at, and shipments from, its Lincoln, Nebraska, facility. The company said this was done "to accelerate maintenance" and make other improvements, adding that it currently "is not possible" to determine when the plant will reopen.

While Novartis announced Sunday's recall, it said that it did so "with the knowledge of the U.S. Food and Drug Administration." This came about after an internal review and assessment of complaints identifying "issues such as broken gelcaps, chipped tablets and inconsistent bottle packaging."

In its news release, Novartis said that the recall and processing upgrades would cost an estimated $120 million, which will be assessed in the fourth quarter of 2011. The number of pills affected by the recall was not released. More information will be announced Monday, Novartis said.