Lonza attests that Nutraceutical International, plus several of its subsidiaries, have infringed its US Patent No. 5,073,376 that covers enteric preparations of L-Carnitine L-Tartrate.

"The validity of all of the claims of the Lonza patent was recently confirmed during re-examination by the US Patent and Trademark Office," said the Swiss firm in a statement this week.

The suit is the first action brought by Lonza against a manufacturer of products containing unlicensed L-Carnitine L-Tartrate, and represents 'a major step in Lonza's continuing efforts to maintain and enforce its patent rights in the L-Carnitine market', said the firm.

The nutrient L-Carnitine is used for weight loss, athletic performance and general cardiovascular health.

Nutraceutical markets products under the trademarks Kal, Nature's Life, Solaray and Natural Max.