Drugmakers Pfizer Inc. and Wyeth have tied the knot, according to AP. Nine months after announcing Pfizer would buy Wyeth for $68 billion, the deal has closed. It's a smart move for Pfizer, changing it overnight from a marketing machine with popular pills to an ultra-diverse health care giant. That's because Wyeth is a major maker of biotech drugs, vaccines and animal and consumer health products. New York-based Pfizer has been struggling to develop new drugs and faces a huge sales drop when its $13 billion-a-year cholesterol fighter Lipitor gets generic competition. Pfizer, the world's biggest drugmaker by revenue, solidifies that position by buying No. 13 Wyeth, of Madison, New Jersey. The combined company can improve its bottom line by slashing jobs and other costs.