For each of the technologies listed below, give its main feature or mode of action that allows it to fulfill its purpose: Hydrophilic Matrix.

The main feature of a Hydrophilic Matrix is its ability to absorb water. This technology is often used in controlled-release drug delivery systems. Here's how it works:

1. When the hydrophilic matrix comes into contact with a liquid, such as water or gastric fluid, it begins to absorb the liquid.

2. As the matrix absorbs the liquid, it swells. This swelling forms a gel-like layer around the matrix.

3. The drug that is embedded within the matrix then begins to diffuse out through this gel layer.

4. The rate of drug release can be controlled by manipulating the properties of the matrix, such as its composition and density.

5. Over time, the outer layers of the matrix continue to dissolve, allowing the drug to be released in a controlled manner.

This ability to control the rate of drug release makes hydrophilic matrices an important technology in the pharmaceutical industry.