Sometimes IV bags are hard for hospitals to come by. Other times it’s injectable folic acid to treat anemias. Right now the tissue-numbing agent lidocaine is in short supply. Shortages of commonplace generic drugs have plagued hospitals in recent years. And with short supplies and fewer suppliers for key drugs, there have been price increases. Now several major hospital systems and philanthropies are taking the problem in hand. They are launching a nonprofit, generic drug company to help fight rising costs and chronic shortages.