why does a dissolvable medication work better when dissolved, but not swallowed?

Question

I take hyoscyamine (an anti-spasmodic used for IBS), which no matter the manufacturer is directed to be dissolved under the tongue, not swallowed. Why does it work best when dissolved?

In: 1

Answer 1

1 – It is absorbed faster through the gums than it is through the stomach lining.

2 – Stomach acid. The medication might not take kindly to stomach acid.