P&G charges that health products maker J&J and its McNeil-PPC unit broke two of its patents concerning the whitener's active ingredient and coating system. The lawsuit was filed in Wisconsin federal court.

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Johnson & Johnson launched Listerine "quick-dissolving" whitening strips last year, touting them as more convenient than others on the market led by P&G's Crest brand Whitestrips because they dissolve after 5 to 10 minutes and can be used on the go. In its earnings report last month, Johnson & Johnson cited Listerine whiteners, which also freshen breath, as among products turning in strong performances in the last quarter. The case is one of several lawsuits P&G has filed against competitors in the past year over product, packaging and marketing disputes.

The dissolving strips followed Crest's launch last year of "daily multicare" strips that can be used for as little as five minutes at a time for whitening. Crest launched its first hydrogen peroxide-based Whitestrips, which recommended 30-minute uses, seven years ago. Listerine and other competitors have taken a bite out of Crest's domination of the home-whitening category, which ACNeilsen research estimates at $240 million a year, increasing at a 19 percent rate. Crest claims a market share of 56 percent, down from nearly 70 percent more than a year ago. "It is a growing category," said Crystal Harrell, a Crest brand spokeswoman. "Whenever you have growth in the category, that's a good thing, but there's more competitive activity."

She said P&G invests heavily in innovation technology and takes infringement of its intellectual property seriously. The lawsuit asks the court to stop the companies from making or selling any products that infringe upon P&G's tooth-whitening patents and also for unspecified money damages.