The pharmaceutical world got a shock this week from reports that Pfizer (NYSE:PFE) had engaged in informal talks with Big Pharma rival AstraZeneca (NYSE:AZN) about a possible $100 billion acquisition. AstraZeneca reportedly expressed no interest in the massive potential buyout, which would have put its pipeline of cancer drugs and other promising medications in Pfizer's hands. But is AstraZeneca's pipeline and current drug portfolio really worth what could have been one of the biggest health care acquisition of all time?

No doubt Pfizer is hungry for a deal, as it holds tens of billions of dollars in untaxed overseas cash and needs to bolster its pipeline. AstraZeneca, however, is in a world of hurt of its own with patent expirations of blockbuster drugs Crestor and Nexium coming in 2016. The company does boast of a number of cancer-fighting drugs in development, among other projects, but in its latest pipeline update AstraZeneca projected that most of its major developmental projects were still some time out from regulatory filing.

Can investors count on AstraZeneca, or will revenue losses and the patent cliff be too much for this stock to overcome in the near future? In the video below, Motley Fool contributor Dan Carroll takes you through what made AstraZeneca so intriguing to buyout-hungry Pfizer and whether this company's performance and pipeline will impress investors in the long term.