Definition
A liquid interface is the boundary between two immiscible liquid phases or between a liquid and another phase (solid or gas).
At this boundary, the physical and chemical properties differ from those in the bulk phases due to molecular interactions unique to the interface.
Types of Liquid Interfaces
Liquid-Gas Interface: Examples include the surface of water exposed to air.
Liquid-Liquid Interface: Occurs between two immiscible liquids like oil and water.
Liquid-Solid Interface: Exists where a liquid is in contact with a solid surface, such as water on glass.
Importance in Pharmaceuticals
Stability of Dosage Forms: Interfaces play a crucial role in the stability of emulsions and suspensions.
Drug Absorption: The interaction of drug molecules at biological interfaces affects absorption and bioavailability.
Surface Phenomena Control: Understanding liquid interfaces helps in manipulating wetting, spreading, and adhesion properties.