The chemicals needed for execution are very easy to create. You can literally kill people with something as simple as a high dose of potassium; it depolarizes the nerve cells in the heart and prevents them from being able to send the electrical signal needed for beating. Unlike the brain, the heart isn't protected by something like a blood-brain barrier that would filter out the potassium.
What's happening is that various pharmaceutical companies don't want their reputations tarnished by being associated with lethal execution, and they're refusing to manufacture and sell the products necessary for it. So I suppose the question becomes: is that a good move? On one hand you can say that these increasingly radical measures used for execution are a direct result of pharmaceutical companies refusing to supply states, thus they're responsible. On another hand you can also say it's a good move because it puts pressure on states to phase out lethal executions because it's becoming increasingly difficult to do and they have to resort to methods that make them look bad. Of course that's only a positive for people that are in the camp of "against lethal execution" in the first place.
