Hospira Inc.said Tuesday that its first-quarter net income fell 73.2 percent, to $40.2 million, a decline the company blamed on costs associated with continued remediation efforts at its manufacturing plants and a lower supply of some key products. The Lake Forest-based maker of generic injectable drugs and intravenous pumps, battered by a string of quality-control problems cited by theU.S. Food and Drug Administration, said sales dropped 3.6 percent, to $965.9 million.