I worked for the company who invented Delsym at the time of invention in the 80's. A great product. It has two main claims to fame. 1st is the delivery system (which is where the name Del sym comes from). It takes the active ingredient and puts it into micro encapsulations, which eliminates the taste, and is a controlled release based on the ionic concentration of the GI track. It truly will last for 12 hours while eliminating the bad taste of the dextromethphem. It will appear to cost more but not when you consort taking it 2 times in 24 hours vs 4 times for others. The 2 oz goes as far as 4 of the others. Probably more than you wanted to know but I was in a position selling it to doctors for the company and had to be able to field all questions.