SAN DIEGO (AP) — Santarus Inc. said Tuesday the proposed over-the-counter version of the heartburn drug Zegerid will be reviewed by the Food and Drug Administration by December. The company’s partner, Schering-Plough Corp., is dealing with the regulatory filing, which had been stalled after the FDA asked for additional information last year. Santarus stands to gain a $20 million milestone payment if the FDA approves the over-the-counter version, along with the possibility of $37.5 million in future sales milestone payments.