How do extended release tablets work?

Question

I know these tablets are especially formulated and coated to dissolve over a certain period of time. I also notice that all I've seen, quite a lot, are too large to pass through the Pylorus. Do they remain in the stomach for most of their release period, slowly being dissolved layer by layer, and only release a constantly steady small amount of their payload into the small intestine to be absorbed and go to work on the body or mind?

Answer 1