It may seem like an easy question to answer, but determining what the largest pharmaceutical company in the world is can be trickier than it looks. The definition of what a "pharmaceutical company" actually is has been changing in the past few years. Some companies, such as Pfizer (NYSE:PFE) and AbbVie, focus on developing and selling branded drugs, while others, such as Johnson & Johnson (NYSE:JNJ) and Merck, have a different strategy and are much more diversified.

So what is a pharmaceutical company, and which one is the largest in the world today? Health-care analyst Max Macaluso weighs in on this debate in the following video.

Editor's note: Pfizer lost patent protection for Lipitor in 2011. The Fool regrets the error.

Max Macaluso, Ph.D., has no position in any stocks mentioned. The Motley Fool recommends and owns shares of Johnson & Johnson. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.