Megan McArdle discusses some of the factors hindering new drug development in her latest article in The Atlantic, "No Refills".
But although she (appropriately) places some of the blame on the government, she also place blame on the drug companies. However, some of the economic concerns of the drug companies are indirectly attributable to downstream effects of other government regulations!
For more details, see "How the FDA Violates Rights and Hinders Health" by Stella Daily in the Fall 2008 issue of The Objective Standard.