Philadelphia—Elsevier, the global health care and scientific publisher and a subsidiary of b-to-b media giant Reed Elsevier, has entered into a definitive agreement to acquire Gold Standard, a U.S-based developer of online clinical drug information products and services for the health care market. Terms were not disclosed, but people familiar with the deal said the sale price would fall somewhere between $50 million and $100 million. Gold Standard serves more than 1,000 hospitals, retail pharmacy chains and consultant pharmacy organizations, health information Web sites, pharmacy and medical schools, and hundreds of thousands of health care professionals and consumers. The deal is expected to close at the end of April. Media investment bank Jordan, Edmiston represented Gold Standard in the transaction.