Income-seeking investors usually don't think of the innovation-dependent pharmaceutical industry as a place to look for businesses with reliable cash flows.Dividend seekers have a good reason to be cautious regarding drugmaker stocks. Profit driven by patent-protected market exclusivity can disappear in the blink of an eye after those patents expire. These two giants of the pharmaceutical industry are made of enough moving pieces that when one blockbuster falls off a patent cliff, there's another on deck to ...