Pfizer showed further weakness in its main business of prescription medicines, sending shares down more than 3 percent on concern over future growth as the company prepares to divest better-performing non-pharmaceuticals businesses, according to Reuters. The world''s largest drugmaker saw sales declines in primary care, specialty care, branded generic and oncology medicines during the second quarter. One of the few bright spots was that drug sales grew in emerging markets. That could mean it is more vulnerable ahead of the U.S. patent expiration in November on its top-selling Lipitor cholesterol fighter. Generic competition has already begun to chip away at overseas sales of the $10 billion-a-year drug. Pfizer said global prescription drug sales fell 3 percent in the quarter to $14.64 billion, and were down 7 percent after stripping out the benefit of the weaker dollar. Lipitor worldwide sales fell 8 percent to $2.59 billion. Those declines were partly offset by a stronger performance in its animal health and nutritional products business. But Pfizer plans to divest those units in the next year or two, through a sale or spin-off. The combined value of the businesses could exceed $16 billion.