Washington, Dec 10 (Prensa Latina) Drug companies are deliberately targeting the U.S. to raise prices and game the patent system to delay generic competition in a way that is "unsustainable, unjustified, and unfair to patients and taxpayers," according to the findings from a new investigation released Friday by House Democrats. The investigation focused on 10 companies that sell 12 of the most expensive drugs to Medicare, including insulin, and found those companies collectively raised prices more than 250 times.