Presented by: SAMIKSHA SAWANT
M.Pharm (IP) 2nd Sem
Guided by: Dr. (Mrs.) INDIRA PARAB
Mr. Green made first gelatin
microcapsules in 1940
It then took 9 years
of research to make
Technique of microencapsulation
is adapted from nature itself
What is microencapsulation?
Microencapsulation is a process
by which individual particles or
droplets of an active material
are isolated by being
surrounded with a coating to
produce a microcapsule.
Reliable means to deliver the drug to the target
site with specificity, if modified, and to maintain the
desired concentration at the site of interest without
Solid biodegradable microspheres have the
potential for the controlled release of drug.
Microspheres received much attention not only for
prolonged release, but also for targeting of
anticancer drugs to the tumour.
Studies on the macrophage uptake of
microcapsules have demonstrated their potential
in targeting drugs to pathogens residing
It is an expensive process
Difficult to obtain continuous and
• The solid core can be mixture of active
constituents, stabilizers, diluents,
excipients and release-rate retardants or
• Compatible, non reactive with core
• Provide desired coating properties like
strength, flexibility, impermeability,
optical properties, non hygroscopicity,
tasteless and stable
Supercritical CO2 assisted
Anti gas solvency
Partial gas saturated solution
Spray drying and
technique jet cutter
A relatively new
to form protective
The methods involve the
reaction of monomeric
units located at the
interface existing between
a core material substance
and a continuous phase in
which the core material is
In- situ polymerisation
The multifunctional monomer dissolved
in liquid core material which will be
then dispersed in aqueous phase
containing dispersing agent.
A co reactant multifunctional amine
will be added to the mixture.
This results in rapid polymerization at
interface and generation of capsule shell
A polyurea shell will be formed when
isocyanate reacts with amine,
polynylon or polyamide shell will be
formed when acid chloride reacts with
In this process no reactive agents are
added to the core material.
polymerization occurs exclusively in the
continuous phase and on the continuous
phase side of the interface formed by the
dispersed core material and continuous
Initially a low molecular weight
prepolymer will be formed, as time goes on
the prepolymer grows in size.
it deposits on the surface of the dispersed
core material thereby generating solid
The process involves dissolving microcapsule coating
(polymer) in a volatile solvent
A core material (drug) to be microencapsulated is
dissolved or dispersed in the coating polymer
With agitation, the core – coating material mixture is
dispersed in the liquid manufacturing vehicle phase to
obtain appropriate size microcapsules.
Agitation of system is continued until the solvent
partitions into the aqueous phase and is removed by
This process results in hardened microspheres which
contain the active moiety.
Suitable for large particles of size
greater than 600 microns.
The particles are tumbled in a pan or
other device while the coating
material is applied slowly
The coating is applied as a solution
or as an atomized spray to the
desired solid core material in the
Usually, to remove the coating
solvent, warm air is passed over the
coated materials as the coatings are
being applied in the coating pans.
In some cases, final solvent removal
is accomplished in drying oven.
Air suspension technique
• In this, the fine core
suspended in a vertical
current of air and
sprayed with the
• After evaporation of
solvent, a layer of
is deposited on core
• Gives improved
control and flexibility
as compared to pan
Anti gas solvency
Mix core and shell materials a
solvent which is miscible in
Now add this to supercritical
fluid at high pressure and
This leads to super saturation
such that precipitation of the
solute occurs . Thus, the
solute must be soluble in the
liquid solvent, but should not
dissolve in the mixture of
solvent and supercritical fluid
Particles from a gas-saturated solution
• This process is carried out by mixing core and
shell materials in supercritical fluid at high
• During this process supercritical fluid
penetrates the shell material, causing
• When the mixture is heated above the glass
transition temperature the polymer liquefies.
• Upon releasing the pressure, the shell
material is allowed to deposit onto the active
Spray drying and congealing
Dispersing the core material in a
liquefied coating Substance
/spraying or introducing the coating
mixture on to core material.
Coating solidification in spray
drying is effected by rapid
evaporation of a solvent in which
the coating material is dissolved.
Coating solidification in spray
congealing method is accomplished
by thermally congealing a molten
coating material or by solidifying a
dissolved coating by introducing the
coating core material mixture into a
Spinning disc method
Suspensions of core particles in
liquid shell material are poured into
a rotating disc.
Due to the spinning action of the
disc, the core particles become
coated with the shell material.
The coated particles are then cast
from the edge of the disc by
After that the shell material is
solidified by external means
This technology is rapid, cost-
effective, relatively simple and has
high production efficiencies.
This is based on Rayleigh instability
A fluid stream of liquid core and
shell materials is pumped through
concentric tubes and forms droplets
under the influence of vibration.
To guarantee production of uniform
beads and to avoid large size
distributions due to coalescence
effects during the flight, the droplets
pass through an electrostatic field to
As a result these droplets do not hit
each other during the flight
Jet cutter technology
• This is a simple technology for bead production that
meets the requirement of producing monodisperse
beads originating from low up to viscous fluids with a
Microencapsulation has been employed to provide
protection to the core materials against atmospheric
effects, e.g., Vitamin A Palmitate.
Separation of incompatible substance has been achieved
To mask the bitter taste of drugs like Paracetamol,
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 e.g. Sodium chloride.
Carbon tetra chlorides and a number of other
substances have been microencapsulated to reduce
their odour and volatility
To reduce volatality of liquids like peppermint oil
Helps to prepare SRDF and enteric coated products,
controlled release products
Used to improve flow properties before compression
Smaller molecules can stay in the blood stream
longer with fewer side effects
Less frequent injection
More sophisticated site targetting
The harsh condition in the stomach denatures most
proteins and peptides hence they require some sort
of depot or extended release can be done by
After hydrolysis in in the lower intestine, the polyunsaturated fats is
digested and absorbed, thereby resulting in higher amounts of
unsaturated fats in milk and meat.
Polyunsaturated vegetable oil was encapsulated in protein coat and
reacted with formaldehyde, thus protecting the unsaturated fats from
bacteria in rumen.
Plant fat contains polyunsaturated fatty acids, but milk and meat
contains only 2-4% of it
MICROENCAPSULATION FOR DECREASING ATHEROSCLEROSIS
• Hughes provided a method of sustained delivery of an
active drug to a posterior part of an eye of a mammal to
treat or prevent a disease or condition affecting mammals.
The method is comprised of administering an effective
amount of an ester prodrug of the active drug such as
tazarotene (prodrug of tazarotenic acid) subconjunctivally
or periocularly since a systemic administration requires
high systemic concentration of the prodrug. The ester
prodrug is contained in biodegradable polymeric
microparticle system prepared using the o/w emulsion
solvent evaporation methods.
• Encapsulation of nucleotides and growth hormone using
simple or double emulsification methods was achieved by
Johnson et al
• A method of encapsulating DNA retaining its
ability to induce expression of its coding
sequence in a microparticle for oral
administration prepared using the w/o/w
emulsion and using biodegradable polymers
under reduced shear is produced by Jones et al
• Reslow et al. utilized starch to encapsulate
vaccines using emulsification method. In process,
an immunologically active substance (vaccine) is
suspended in an aqueous starch solution with an
amylopectin content exceeding 85% by weight.
The starch droplets containing the vaccine are
allowed to gel as the starch has capacity to gel
Brand name API Manufacturer
Colon specific drugs Alza corp.
Paclitaxel Macro Med Inc.
Clopigrel clopidogrel+ Aspirin Lupin pinnacle
Clobitab clopidogrel+ Aspirin Lupin pinnacle
Atoplus Atorvastatin Triton (calyx)
• The Theory and Practice of Industrial Pharmacy,
lachman/lieberman, 4th edition, pg no. 579-596
• Microencapsulation- Processes and Applications,
edited by Tan E. Vandegar, pg no. 1-20 and 57-59
• Multiparticulate drug delivery, edited by Iisaac
Ghebre- Sellassie, pg no. 51-109
• The Design and Manufacture of Medicines, Michael
Aulton and Kevin M.G.Taylor, 4th edition, pg no. 578-
• Polymeric Drug Delivery- Particulate Drug Carriers,
edited by Sonke Svenson, pg no. 242-245
• Microencapsulation: a vital technique in novel drug delivery
system P.Venkatesan, R.Manavalan and K.Valliappan
• Microencapsulation: Process, Techniques and Applications
Hammad umer*1 , Hemlata Nigam2 , Asif M Tamboli2 , M.
Sundara Moorthi Nainar2
• Microencapsulation: a review jyothi sri.s* 1 , a.seethadevi 1 ,
k.suria prabha 1 , p.muthuprasanna 1 and ,p.pavitra2
• Microencapsulation – A Novel Approach in Drug Delivery: A
Nitika Agnihotri, Ravinesh Mishra*, Chirag Goda, Manu Arora
• Reslow M, Bjorn S, Drustrup J, Gustafsson NO,
Jonsson M, Laakso T, inventors. A controlled
release, parenterally administrable microparticle
preparation. EP1328258. 2008