my sister is a pahrmacy student..so any pharma students can access this

1. MICROSPHERES

2. Microcapsule:
Microcapsule is a spherical particle with size
varying from 50nm to 2mm, containing a
core substance.

3.  The microspheres are characteristically free
flowing powders consisting of proteins
or synthetic polymers, which are
biodegradable in nature, and ideally having a
particle size less than 200 micrometer.
 Polymers of both natural and synthetic
origin can be used.

4. Materials Used:
Non-
biodegradable
Synthetic
Biodegradable
Polymers
Proteins &
Natural
Carbohydrates

5. • Synthetic non-biodegradable materials used are
PMMA, Acrolein etc and biodegradable
materials used are Lactides and glycolides and
their copolymers.
• Proteins like albumins, gelatin and
carbohydrates like starch, glucose, chitosan
etc are also used.

6. Prerequisites for Ideal Micro particulate carriers:
o Longer duration of action
o Increase of Therapeutic efficiency.
o Biocompatibility
o Sterilizability
o Relative Stability
o Water solubility or dispersability

7. Methods of Preparation
Preparation
methods
Emulsion
Polymerization
techniques
Single Double Normal and
Emulsion Emulsion Interfacial

8. Drug Release Kinetics
 Liberation due to Polymer erosion
 Self diffusion through the pore.
 Release from the surface of the polymer
 Pulsed delivery initiated by application
of an oscillating or sonic field

9. Drug Release
Reservoir
type
Matrix
Type

10. Polymeric Microspheres
Albumin
Gelatin Starch
Polylactide &
Carrageenan Alginate
Polyglycolide

11. Preparation of Microspheres
Aq. Soln of 8% w/v acrolein 0.5%
sodium bisulphite polyglutaraldehyde
conjugate
pH adjusted to 10.5
Dialysis and centrifugation
Microspheres

12. Characterization
Particle Size and shape:
• The most widely used procedures are conventional
light microscopy and scanning electron microscopy.
• Confocal laser scanning microscopy is a non
destructive visualization technique.
• Confocal fluorescence microscopy is used for
Structural characterization.

13. Capture Efficiency
 It
is the percent entrapment determined by allowing
washed microspheres to lyse.
 The lysate is subjected to the determination of
active constituents.
 % entrapment = Actual content
________________ * 100
Theoretical content

14.  Density determination is done by using a
multivolume pychnometer.
 Micro electrophoresis is an apparatus used to
measure electrophoretic mobility
of microspheres.
 Surface associated amino acid residue is
determined by C – Acetic acid conjugate.
 The accuracy depends on the time
allowed for conjugation.

15. APPLICATIONS

16. Polymeric Carrier for Antigens
ANTIGEN POLYMER USED PREPARATION
METHOD
Staphylococcus dl- PLGA Solvent evaporation
enterotoxin B
Diphtheria toxoid dl- PLGA W/O/W emulsion
Hepatitis B Surface Phase Separation
antigen PGA emulsion
Tetanus toxoid PLA, PLGA Emulsion
Bovine serum albumin PLA Adsorption

17. Stability
Stability is affected by many factors such as:
o Polymer
o Moisture
o Lyophilization
o pH
o Shearing
o Temperature
o Rotation
o Salt

18. Advantages
 Improved antigenicity by
adjuvant action.
 Modulation of antigen release
 Stabilization of antigens.

19. Efficient transport across microvascular
barrier can be achieved by:
 Magnetic dragging of the magnetic microparticles
directly through endothelium and basement
membrane.
 Facilitated transport of specific ligand drug
conjugates or coated microspheres across endothelium
as a result of ligand binding to luminal surface antigen
or receptors.
 Transient regional opening of endothelium function
combined with vascular infusion of drug carrier that
becomes sequestered in the extracellular complex.