Microencapsulation is a process of enclosing core materials within microcapsules, utilizing both chemical and physical methods to control the release and protect the core from external factors. Applications range from pharmaceuticals to food products, improving stability, masking tastes, and enhancing handling properties. Despite advancements, challenges remain in selecting appropriate materials and techniques for effective microencapsulation.

1. MICROENCAPSULATION
FACULTY GUIDE: PRESENTED BY:
DR. MARYAM SARWAT ANSH DEV
A4513309001

2. “ Micro encapsulation is at crossroads
of art, science and technology. The
right choice between process and
chemistry, defining the processing
conditions and parameters at a wide
range of machines, is possible only for
those with a sound scientific
background, combined with a long
time experience of trial and error.”

3. • It is the process of enclosing a core material inside a
miniature capsule called microcapsules
• It is a physic-chemical process, total surface area determines
most of the time the wall thickness and as such the resistance
of the micro capsule in its final application.

4. 1. CORE MATERIAL: The substance that is encapsulated.
2. COATING: The material encapsulating the core
3. SHELLS: Microcapsules may have one wall or multiple shells
arranged in strata of varying thicknesses around
the core.

6. • In some cases
 to isolate the core from its surroundings
 isolating vitamins from the deteriorating effects of oxygen
 retarding evaporation of a volatile core
 improving the handling properties of a sticky material
 isolating a reactive core from chemical attack
• Others
 not to isolate the core completely but to control the rate at
which it leaves the microcapsule
 increasing the selectivity of
an adsorption or extraction process

7. • CHEMICAL METHODS
 Coecervation
 Interfacial polymerization
 Phase separation
 In situ polymerization
 Centrifugal force processes
• PHYSICAL METHODS
 Spray drying
 Fluid bed coating
 Centrifugal extrusion processes
 Spinning disk method

8. APPLICATION :
Capsules for carbonless paper and for many other
applications are produced
STEPS
1. takes advantage of the reaction of aqueous
solutions of cationic and anionic polymers such as gelatin
and gum arabic.
2. polymers form a concentrated phase called the
complex coacervate. The coacervate exists in
equilibrium with a dilute supernatant phase.

10. This technique is characterized by wall formation via the
rapid polymerization of monomers at the surface of the
droplets or particles core material, and this solution is
dispersed in an aqueous phase.

11. This method utilizes two polymers that are soluble in a
common solvent; yet do not mix with one another in the
solution.
FIGURE: PHASE SEPARATOR

12. In situ polymerization is a chemical encapsulation technique
very similar to interfacial polymerization. The distinguishing
characteristic of in situ polymerization is that no reactants are
included in the core material.

13.  Centrifugal force processes were developed
in the 1940s to encapsulate fish oils and
vitamins, protecting them from oxidation.
 This techniques is common for both chemical
and physical techniques.

14. An emulsion is prepared
by dispersing the core
material, usually an oil or
active ingredient
immiscible with water;
into a concentrated
solution of wall material
until the desired size of oil
droplets are attained. The
resultant emulsion is
atomized into a spray of
droplets by pumping the
slurry through a rotating
disc into the heated
compartment of a
spray
drier.

15. Fluid bed coating, another mechanical encapsulation method,
is restricted to encapsulation of solid core materials, including
liquids absorbed into porous solids. This technique is used
extensively to encapsulate pharmaceuticals.

16. The internal phase is dispersed into the liquid wall
material and the mixture is advanced onto a turning
disk. Droplets of pure shell material are thrown off of
the rim of the disk along with discrete particles of
core material enclosed in a skin of shell material.
After having been solidified by cooling, the
microcapsules are collected separately from the
particles of shell material.

17. • Microorganism and enzyme immobilization
• Protection against UV, heat, oxidation, acids, bases
(e.g. colorants and vitamins).
• Improved shelf life due to preventing degradative
reactions (dehydration, oxidation)
• Masking of taste or odours.
• Improved processing, texture and less wastage
of ingredients.
• Handling liquids as solids
• Enhance visual aspect and marketing
concept.

18. • Microencapsulation is the packaging of small
droplets of liquid or particles with a thin film.
• The lowest particle size of microcapsules is 1µm
and the largest size is 1mm.
• Microcapsules consist of a core and a wall (or
shell). The configuration of the core can be a
spherical or irregular particle, liquid-phase
suspended solid, solid matrix, dispersed
solid and aggregates of solids or liquid
forms.

20. APPLICATION OF
MICROENCAPSULATION
• To mask the bitter taste of drugs like Paracetamol,
Nitrofurantoin etc.
• To reduce gastric and other gastro intestinal (G.I) tract
irritations, For eg., sustained release Aspirin preparations
have been reported to cause significantly less G.I. bleeding
than conventional preparations
• A liquid can be converted to a pseudo-solid for easy
handling and storage, eg. Eprazinone.
• Hygroscopic properties of core materials may be
reduced by microencapsulation eg. Sodium chloride.
• Carbon tetra chlorides and a number of other
substances have been microencapsulated to
reduce their odor and volatility.

21. CONCLUSION
Microencapsulation system offers potential
advantages over conventional drug delivery
systems and also established as unique carrier
systems for many pharmaceuticals (targeted drug
delivery systems). Although significant advances
have been made in the field of
microencapsulation, still many challenges
need to be rectified during the appropriate
selection of core materials, coating materials
and process techniques.