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Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
Microspheres
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Microspheres

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

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

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  • 1. MICROSPHERES
  • 2. Microcapsule:Microcapsule is a spherical particle with sizevarying from 50nm to 2mm, containing acore substance.
  • 3.  The microspheres are characteristically free flowing powders consisting of proteinsor synthetic polymers, which are biodegradable in nature, and ideally having aparticle size less than 200 micrometer. Polymers of both natural and syntheticorigin can be used.
  • 4. Materials Used: Non- biodegradable Synthetic Biodegradable Polymers Proteins & Natural Carbohydrates
  • 5. • Synthetic non-biodegradable materials used arePMMA, Acrolein etc and biodegradablematerials used are Lactides and glycolides andtheir copolymers.• Proteins like albumins, gelatin andcarbohydrates like starch, glucose, chitosanetc 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. CharacterizationParticle 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 allowingwashed 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 mobilityof microspheres. Surface associated amino acid residue isdetermined by C – Acetic acid conjugate. The accuracy depends on the timeallowed 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. StabilityStability is affected by many factors such as:o Polymero Moistureo Lyophilizationo pHo Shearingo Temperatureo Rotationo Salt
  • 18. Advantages Improved antigenicity by adjuvant action. Modulation of antigen release Stabilization of antigens.
  • 19. Efficient transport across microvascularbarrier 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.

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