Chattanooga-based Chattem has carried out the biggest product launch in its 130-year history and one of the largest ever in the city. “It’s an exciting time for us,” Chattem President Bob Bosworth said about the massive rollout of allergy drug Allegra last week to more than 25,000 stores nationwide. First-day shipments to stores hit about $100 million, according to the company. Bosworth said Allegra, shifting from a prescription drug to an over-the-counter medicine, is targeting the No. 1 slot in its segment by lapping competitors Claritin and Zyrtec. Zan Guerry, Chattem’s chief executive, said the company is aiming for annual...