Research spending by the pharmaceutical industry hit a record level of $43 billion in 2006, but there were just 18 new drugs approved by the FDA year. That's about a third of what the industry saw in 1996, a peak year for new drug approvals. Investment in R&D has risen steadily, but the fall-off in approvals in recent years has raised concerns about the efficiency of biomedical research. Those concerns have driven the FDA's critical path initiative, which has focused on using new technology to close the widening gap between investment and return on R&D. The pharmaceutical industry has turned to the biotech sector to provide some of the innovation it needs. But some fear that as the industry matures, its output will slow. And if the robust merger and acquisition activity continues, there will be fewer products from these companies that will make it to market.