What is coacervation method?
Coacervation is a process during which a homogeneous solution of charged macromolecules undergoes liquid–liquid phase separation, giving rise to a polymer-rich dense phase at the bottom and a transparent solution above.
Which method is used for coacervation-phase separation?
The addition of a polymer which has a high affinity for water has been used to induce coacervation-phase separation of the coating polymer, gelatin. Thus, a core was incorporated in a gelatin solution containing 10 to 25~ polyethylene glycol to cause phase separation (Kondo, 1979a).
What causes coacervation?
Phase separation in simple coacervation is brought about by addition of a salt, pH, or temperature change in the polymeric solution (such as alginate and calcium) while in complex coacervation is brought about by anion–cation interactions (such as gelatine and gum Arabic or chitosan and alginate).
What is simple coacervation?
Simple coacervation involves the use of single polymer such as gelatin or ethyl cellulose. While, complex coacervation involves neutralization of two oppositely charge polymer in aqueous solution. The widely used method is neutralization between negatively charge Arabic gum and positively charge gelatin .
How many phases are there in microencapsulation by coacervation?
STEPS IN COACERVATION: Coat formation during coacervation-phase separation process consists of three steps carried out under continues agitation: STEP:1 Formation of three immiscible chemical phases (vehicle, core and liquid coating). STEP:2 Deposition of the coat material STEP:3. Rigidisation of the coat material.
What is complex coacervation?
Complex coacervation is a highly promising microencapsulation technique that is extensively employed in pharmaceutical, food, agriculture and textile industries. The process involves the interaction of oppositely charged polyelectrolytes in aqueous form.
Which of the following complex forming agent is used in coacervation method?
1 Formaldehyde or Glutaraldehyde-Based Techniques. Complex coacervation. This technique employs two natural biodegradable polymers of opposite charge. One commonly used pair of such polymers is alginate and gelatin.
Which type of polymer is used in complex coacervation method?
Complex coacervation Gelatin is normally the cationic polymer used. A variety of natural and synthetic anionic water-soluble polymers interact with gelatin to form a complex coacervate, but the food industry appears to use gum arabic exclusively.
Which of the following technique is used for coacervation microencapsulation technique?
MICROENCAPSULATION TECHNIQUES: 1. Air suspension process 2. Coacervation-phase separation process 3. Pan coating 4.
When was coacervation introduced in pharmaceutical formulation?
1 The term coacervation was introduced in 1929 by Bungenberg de Jong and Kruyt, for a process in which aqueous colloidal solutions separate, upon alteration of the thermodynamic condition of state, into two liquid phases, one rich in colloid, i.e., the coacervate, and the other containing little colloid.
What are coacervates and microspheres?
Coacervates and microspheres are tiny spherical structures formed by the aggregations of lipids and proteins respectively. They are cell-like structures. But they do not contain all the properties of a living cell. Coacervates have a single membrane like boundary while microspheres have double membranes.