Biodegradable polymeric delivery system

1. • Presented to: Dr. Javed Ali
Presented by: Shakeeb Ahmed
Jamia
BIODEGRADABLE
POLYMERIC DELIVERY
SYSTEM

2. BIODEGRADABLE POLYMERS
Nature’s way:
“Every resource made by nature returns
to nature”

3. HOWLONGDOESITTAKE? POLYMERIC MATERIAL DEGRADATION TIME
Cotton rags 1-5 months
Paper 2-5 months
Rope 3-14 months
Orange peels 6 months
Wool socks 1 to 5 years
Cigarette butts 1 to 12 years
Plastic coated paper milk cartons 5 years
Plastic bags 10 to 20 years
Nylon fabric 30 to 40 years
Aluminum cans 80 to 100 years
Plastic 6-pack holder rings 450 years
Glass bottles 1 million years
Plastic bottles May be never

4. HISTORY
• When polymers were synthesized from glycolic acid in
1920s, at that time, polymer degradation was viewed
negatively as a process, where properties and
performance deteriorated with time.

5. BIODEGRADABLE POLYMER: DEFINITION
• “Polymers that degraded/eroded by enzymes
introduced in vivo or surrounding living cells or
• Degraded/eroded by non enzymatic process into
oligomers ,after their intended purpose to result in
natural byproducts (gases : CO2, N2; water, biomass, and
inorganic salts)”
• Byproducts are metabolized and removed from the
body via normal metabolic pathways.

6. ADVANTAGES
Less toxic compared to non-biodegradable polymers
Much higher doses of the drug can be delivered locally
Controlled drug release from the formulation
Stabilization of drug
Localized delivery of drug
Decrease in dosing frequency
Reduce side effects
Improved patient compliance
Polymer retain its characteristics till the depletion of
drug

7. BIODEGRADABLE POLYMERS:
classification
A: BASED ON ORIGIN
Natural origin : Collagen, Albumin, Casein, etc.
Semi-synthetic polymers : Gelatin, Dextran , Chitin, Alginate,
Chitosan , etc.
Synthetic polymers :
Aliphatic polyesters : PGA, PLA,PCL, etc.
Polyphosphoesters , polyanhydrides , polyphosphazenes,
polyaminoacids
B. BASED ON ENVIORNMENTAL FACTORS:
Thermosensitive polymer: Polyacrylamide , etc.
Electrically and chemically controlled: Poly(pyrrole), collagen, etc.
pH sensitive polymer: poly (2-ethylacrylic acid), etc.
C. MISCELLANEOUS:
Polymeric phospholipids, Polyethyleneamine, Polyamidoamine, PEG

8. DIFFERENT MECHANISMS OF
DEGRADATION
1. Chemical degradation
2. Physical degradation
3. Enzymatic degradation

9. ENZYMATIC OR CHEMICAL
DEGRADATION
• Chemical or enzymatic degradation–mediated by
water, enzymes, microorganisms.
CLEAVAGE OF CROSSLINKS
TRANSFORMATION OF SIDE CHAINS
CLEAVAGE OF BACKBONE

10. BIODEGRADABLE POLYMERS
• Acetal:
Hemiacetal:
• Ether
• Nitrile
• Phosphonate
• Polycyanocrylate
OH2
+C
O
H H
R' OHO C O
H
H
R R' R OH +
OC
C
C C
C
OH
OH
OH
OH
OH OHC
C
C C
OH
OH
OH
OH
H2O
+
C==O
H
H2O
R C O C R'
H H
H H
OH2
R C OH
H
H
R' C OH
H
H
+
R C R
C N
H
R C R
C O
H
NH2
R C R
C O
H
OH
OH2 OH2
RO P OR'
O
OR''
OH P OH
O
OR''
OH2
+ +R OH OH R'
R C C C C R'
CN
C
OR''
CN
H
H
O C
OR'''
O
H
H
OH2
R C C C
CN
C
OR''
H
H
O
H
H
OH C R'
CN
C
OR'''
O
+

11. 1) Bulk erosion
• Degradation takes place throughout
the whole of the sample.
• Water intake is faster than the polymer
chain scission
• Eg : polyesters, PLA, PLGA, polylactones,
poly(amino acids), and
polyphosphazenes
2) Surface erosion
– Sample is eroded from the surface.
– polymer degradation is much faster
than water intake
– E.g. Polyanhydrides, polyorthoesters 11
PHYSICAL DEGRADATION

12. METHODS OF STUDYING POLYMER
DEGRADATION
• Morphological changes (swelling, deformation,
bubbling, disappearance)
• Weight loss
• Thermal behavior changes (DSC)
• Molecular weight changes
– Size exclusion chromatography
– Gel permeation chromatography
– Mass spectroscopy
• Change in chemistry (IR, NMR)

13. MOLDING (Formation of drug polymer matrix)
Methods:
1. Compression molding
2. Melt molding
3. Solvent casting
1.Compression molding
• Polymer and drug particles are milled to a particle size
range of 90-150 µm
• Drug/polymer mix is compressed at approx. 30,000 psi
• Formation of some types of tablet/matrix

14. MELT MOLDING

15. SOLVENT CASTING

16. APPLICATIONS OF BIODEGRADABLE
POLYMERS
• Polymer system for gene therapy.
• Biodegradable polymer for ocular, tissue engineering, vascular,
orthopedic, skin adhesive & surgical glues.
• Biodegradable drug delivery system for therapeutic agents such as
anti-tumor, antipsychotic agent, anti-inflammatory agent.
• Polymeric materials are used in and on soil to improve aeration,
and promote plant growth and health.
• Many biomaterials, especially heart valve replacements and blood
vessels, are made of polymers like Dacron, Teflon and polyurethane.

17. APPLICATION

18. APPLICATION

19. APPLICATION: as a Drug Delivery System

20. APPLICATION: as an ocusert

21. BIODEGRADABLE POLYMERS:
Application in drug delivery

22. BIODEGRADABLE POLYMERS:
Application in drug delivery

23. BIODEGRADABLE POLYMERS:
Application in drug delivery

24. INDIVIDUAL APPLICATION OF
BIODEGRADABLE POLYMERS
POLYMERS APPLICATION
Collagen In wound repairing
Chitosan Gelling agent
Dextran Plasma volume expander
Lectins As a mucoadhesive
Cyclodextrins, guar gum, pectin,
insulin
Delivery of drug to colon
Poly -€-caprolactone Microspheres, implants
Rosin As an adhesive in TDDS

25. INDIVIDUAL APPLICATION OF
BIODEGRADABLE POLYMERS
POLYMERS APPLICATION
PLA, PLGA
• Excipients for injectable drugs
• PLA + Doxycycline…….periodontal disease
• PLGA + Growth hormone…Growth
deficiency
• PLA + Leuprolide acetate….Prostate
cancer

26. CONCLUSION
• Numerous synthetic biodegradable polymers are available and still
being developed for sustained and targeted drug delivery applications.
• Biodegradable polymers have proven their potential for the
development of new, advanced and efficient DDS and capable of
delivering a wide range of bioactive materials.
• However, only few have entered the market since many drugs faces the
problem of sensitivity to heat, shear forces and interaction between
polymers.
• These problems can be overcome by fully understanding the
degradation mechanism to adjust the release profile.

27. REFERENCES
• Kumari A, Yadav SK, Yadav SC (2010); “Biodegradable
polymeric nanoparticles based drug delivery systems”;
Colloids Surf B Biointerfaces