When something is solubilized, it means it has been turned into a liquid by mixing it with a liquid.
Solubilized things are usually easier to use or work with.
Examples:
The sugar solubilized in the water.
She solubilized the medicine in the liquid.
The salt solubilized in the soup.
The chocolate solubilized in the warm milk.
The entire mountain solubilized in the heavy rain.
He solubilized the paint in the can and then painted the wall.