Surface and Interfacial tension [Part-4](Adsorption at liquid interface, Surface active agents )

The document discusses surface and interfacial tension in physical pharmaceutics, focusing on adsorption at liquid interfaces and surface active agents (surfactants). It defines adsorption as the deposition of molecules at the liquid surface, categorizing it into positive and negative types based on their behavior at the interface. Additionally, it classifies surfactants into ionic (anionic, cationic, ampholytic) and non-ionic types, detailing their properties and examples.