microencapsulation, mucosal drug delivery system , implantable drug delivery system unit 2 noval drug delivery system

microencapsulation
mucosal drug delivery system
implantabale drug delivery system
unit 2 noval drug delivery system
7th semester b pharmacy
batchlor of pharmacy
unit 2 ppt noval drug delivery system 2024

1. SCHOOL OF PHARMACY DESH BHAGAT UNIVERSIY MANDI GOBINDGARH
PUNJAB
[email protected]

2. }{ Introduction }{
Microencapsulation is a process in which very tiny droplets or particles of
liquid or solid material are surrounded or coated with polymeric, waxy or
protective material
The product obtained by this process is called as micro particles,
microcapsules
. Particles having diameter between 3-800µm are known as micro particles or
microcapsules or microspheres.
Particles larger than 1000µm are known as Macroparticles Change in simple
language

3. Different microcapsule and capsule
FIG 1.1 : micro capsule

4. ✓ To Increase of
bioavailability.
✓ To alter the drug release.
✓ To improve the patient's
compliance.
✓ To produce a targeted drug
delivery.
✓ To reduce the reactivity of
the core in relation to the
outside environment.
✓ Possible cross reaction between core and
shell material.
✓ Difficult to achieve continuous and
uniform film .
Shelf life of hygroscopic drugs is reduced .
More production costs.
✓ More skill and knowledge is required.
AdvantagesDisadvantages

5. FIG 2.1 : Micro Capsule

6. Fundamental considerations

7. ❑ General Methods
➢ Single Emulsion Techniques
➢ Double Emulsion Techniques
Physical Methods:
Phase separation coacervation technique
Mechanical Methods:
Spray drying & congealing
Fluidized Bed Technology
Solvent evaporation
Pan Coating
Rotational Suspension Separation
Extrusion
Nozzle Vibration Technology

MICROENCAPSULATION
TECHNIQUES

8. Pan coating
✓The coating solution is applied as atomized
spray to the solid core material in the coating
pan.
✓To remove the coating solvent warm air is
passed over the coated material.
✓By using this technique larger sized particles
will be coated effectively.

9. Mucosal drug delivery system
INTRODUCTION :
✓Delivery of drugs via the absorptive mucosa in various easily accessible body cavities, like the ocular, nasal, buccal, rectal and
vaginal mucosae, has the advantage of bypassing the hepato-gastrointestinal first-pass elimination associated with oral
administration.
✓Mucosal membranes can be useful sites with good accessibility for easy application of drug delivery systems, especially for
those with bio mucoadhesive properties.
✓ Mucoadhesive drug delivery systems utilize the property of bio adhesion of certain polymers which become adhesive on
hydration and hence can be used for targeting a drug to a particular region of the body for extended periods of time and can be
exploited. for the noninvasive systemic delivery of organic- and peptide-based drugs, with rapid absorption as well as sustained
drug action

10. ADVANTAGES
✓ Over hydration may lead to formulation slippery
surface and structural integrity of the formulation may
get disrupted by the swelling and hydration of the bio
adhesion polymer.
✓ Eating and drinking may become restricted
✓ Drug which irritate mucosa or have a bitter or
unpleasant taste or an
✓Obnoxious odour cannot be administered by this route.
✓ Only drug which are absorbed by passive diffusion can
be administered by this route.
DISADVANTAGES
✓Mucosal drug delivery offers
several advantages over other
controlled release systems:
✓High drug flux at the absorbing
tissue.
✓Painless and ease of administration.
✓Low enzymatic activity and avoid
of first pass metabolism.
✓Targeting and localization of the
dosage form at a specific site.
✓Termination of therapy is possible.

11. PRINCIPLE OF BIOADHESION
❖ There are six classical theories adapted which explain the phenomenon of adhesion:
✓Electronic theory- When both mucoadhesive and biological materials come into
contact, they transfer electrons leading to the building of a double electronic layer at
the interface, where the attractive forces within this electronic double layer determines
the mucoadhesive strength.
✓Adsorption theory- The mucoadhesive device adheres to the mucus by secondary
chemical interactions, such as in van der Waals and hydrogen bonds, electrostatic
attraction or hydrophobic interactions.
✓Wetting theory : ability of mucoadhesive polymers to spread and develop immediate
attachment with the mucus membranes
✓Diffusion theory: Physical entanglement of mucin strands and the flexible polymeric
chain
✓Fracture theory : analyses the maximum tensile stress developed during detachment of
mucoadhesive drug delivery systems from the mucosal surfaces

12. ✓Bio adhesion is the state in which two materials, (at least one of which is biological in nature), are held together for a
extended period of time by interfacial forces.
✓ The term bio adhesion implies attachment of drug-carrier system of specific biological location. This biological surface
can be epithelial tissue or the biological surface can be epithelial tissue or the mucous coat on the surface of tissue.
✓ If adhesive attachment is to mucous coat then phenomenon is referred as muco adhesion.
✓Mechanisms of Bio adhesion
✓ The mechanism responsible in the formation of bio adhesive bonds are not fully known, however most research has
described bio adhesive bond formulation as a three step process.
✓Step 1- Wetting and swelling of polymer
✓Step 2 -Interpenetration between the polymer chains and the mucosal membrane
✓Step 3- Formation of chemical bonds between the entangledchains.
CONCEPT OF BIOADHESION
Fig : 3.1

13. TRANSMUCOSAL PERMEABILITY
► Mucosal routes provide the potential pathways to bypass hepato gastrointestinal
first μου elimination following oral administration. Transmucosal drug delivery has
the potential to achieve greater systemic bioavailability for orally metabolized drugs,
including organic- and peptide-based pharmaceuticals
.► There are two routes potentially involved in drug permeation across epithelial
membranes:
a)Transcellular route
b)b) Paracellularroute
Transcellular route : for compounds
paracellular route : for lipophilic compounds
Fig : 4.1

14. Implantable drug delivery system
INTRODUCTION
✓Implants are small sterile solid masses consisting of a highly purified drug made by compression or molding or extrusion
✓Implants are intended for implantation in the body (subcutaneous or intramuscular tissue) by a minor surgical incision or
injected through large bore needle.
✓Implants are developed with a view to provide continuous release of drug into the bloodstream over long period of time
without the repeated insertion of needles.
✓Well suited for insulin, steroids, chemotherapeutics, antibiotics, analgesics, total parenteral nutrition and heparin.
✓Allow targeted and localized drug delivery and may achieve a therapeutic effect with lower concentrations of drugs.
✓It avoids first pass metabolism and chemical degradation in the stomach and intestine, thus, increasing bio availability.
✓ADVANTAGES AND DISADVANTAGES: ❖
✓ Advantages:
✓1. More effective and more prolonged action.
✓2. Better control over drug release3. A significantly small dose is sufficient.
✓Disadvantages:
✓1. Chances of device failure
✓2. Limited to potent drugs
Fig: 5.1

15. Concept of implants
Implants for drug delivery are several types
❖ In situ forming implants:
➢ In situ precipitating implants
These implants are formed from drug containing in a biocompatible solvent.
The polymer solution form implants after subcutaneous (sc) or intramuscular (IM) injection and contact
with aqueous body fluids via the precipitation of polymers
.In situ precipitating implants are formulated to overcome some problems associated to the uses of
biodegradable microparticles:
✓ Requirement for the reconstitution before injection Inability to remove the dose one injected . Relatively
complicated manufacturing procedures to produce a sterile, stable and reproducible product . In situ
microparticle implants :
This type of implants is formed to overcome the disadvantages associated with in situ precipitating
implants . These are:
✓ High injection force.
✓ Irregular shape of the implants.
Undesirable high initial burst release of drugs.

Fig : 6.1

16. Solid implants :
Solid implants are generally cylindrical monolithic devices implanted by a minor surgical incision
or injected via a large bore needle into the sc or im tissues . Subcutaneous tissue is an ideal
location because of its easy access implantation, poor infusion, slower drug absorption and low
reactivity towards foreign materials.
Infusion devices:
Infusion devices are intrinsically powered to release the drugs at a zero order rate and the drug
reservoir can be replenished from time to time .
Depending upon the mechanism by which these implantable pumps are power to release the
drugs.
OSMOTIC PUMPS :
these are designed mainly by a semi-permeable membrane that surrounds a drug reservoir . The membrane
should have an orifice that will allow drug release Osmotic gradients will allow a steady inflow of fluid
within the implant . This type of device allows a favorable release rate but the drug loading is limited . The
historical development of osmotic systems includes seminal C contributions such as the Rose-Nelson pump,
the Higuchi- Leeper pumps, the Alzet and Osmet systems
Fig : 6.1
Fig : 6.2