Microencapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules, with useful properties.
Microencapsulation can also be used to enclose solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, in order to reduce dosing frequency and prevent the degradation of pharmaceuticals.
The enclosed material in the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is sometimes called a shell, coating, or membrane.
Microcapsule: Hollow microparticle composed of a solid shell surrounding acore-forming space available to permanently or temporarily entrapped substances.
Ionotropic gelation occurs when units of uric acid in the chains of the polymer alginate, crosslink with multivalent cations.
The basis of this method is the classical Schotten-Baumann reaction between an acid chloride and a compound containing an active hydrogen atom, such as an amine or alcohol, polyesters, polyurea, polyurethane.
When the reaction is performed at the interface of an emulsion, the acid chloride reacts with the various functional groups of the protein, leading to the formation of a membrane.
Flow of artificial microcapsules in microfluidic channels: In a few microencapsulation processes, the direct polymerization of a single monomer is carried out on the particle surface.
Many walls are ruptured easily by pressure or shear stress, as in the case of breaking dye particles during writing to form a copy.
Capsule contents may be released by melting the wall, or dissolving it under particular conditions, as in the case of an enteric drug coating.
[7] In other systems, the wall is broken by solvent action, enzyme attack, chemical reaction, hydrolysis, or slow disintegration.