I checked Wikipedia and found this Simethicone is an anti-foaming agent that decreases the surface tension of gas bubbles, causing them to combine into larger bubbles in the stomach that can be passed more easily by burping. Simethicone does not reduce or prevent the formation of gas in the digestive tract, rather, it increases the rate at which it exits the body. However, simethicone can relieve pain caused by gas in the intestines by decreasing foaming which then allows for passing of flatus. Simethicone is not absorbed by the body into the bloodstream, and is therefore considered relatively safe, with sources reporting the worst side effects as bloating, constipation, diarrhea, gas and heartburn. While sold as a treatment for colic, randomised controlled trials have not borne this claim out.
The only thing gas drops do is change the surface of the formula, not allowing it to bubble up so you can put it directly into the bottle. I even checked on the Mylecon site and they suggested the same thing.
I just thought I would pass this along. Happy Mother's Day to all!