Health Resource Publishing Co., St. Louis, a unit of Catalina Marketing that has been testing "Health Resource" customized newsletter targeted to pharmacy customers, said it is beginning a nationwide roll-out plan. A 40-store test in seven chains began in February 1995; 14 retailers are now being added, including Vons, Pathmark, Kroger-Cincinnati and Columbus (Ohio), Save Mart, Phar-Mor, SuperD, and Harco. The laser-printed newsletter is triggered by the National Drug Code. When a prescription is processed, a personalized newsletter with relevant editorial and product advertising is printed in the pharmacy and handed to the customer along with the filled prescription. Each newsletter contains four ad sections.