This document discusses biodegradable polymers. It defines biodegradable polymers as polymers that break down into biologically acceptable molecules via normal metabolic pathways. The document classifies biodegradable polymers as natural or synthetic and lists examples of each. It also discusses the ideal characteristics, mechanisms of degradation, factors affecting biodegradation, and applications of biodegradable polymers.

1. Presented By- Chetan Vishwanath Pawar
Guided By- Mrs. S S MUTHA MADAM
M.Pharmacy Sem -I
Department of Pharmaceutics
PDEA’s S.G.R.S. College of Pharmacy Saswad.
Biodegradable Polymers

2.  INTRODUCTION
 Ideal characteristics
 Classification
 Mechanism of Degradation
 FACTORS AFFECTING BIODEGRADATION OF
POLYMERS
 ADVANTAGES
 APPLICATIONS OF BIODEGRADABLE
POLYMERS

3.  Polymers are very large molecules made when
hundreds of monomers join together to form
long chains
 Polymers are complex and giant molecules
usually with carbons building the backbone,
different from low molecular weight
compounds.
 The small individual repeating units/moleules
are known as monomers(means single part).

4. Linear
◦ High Density Polyethylene (HDPE), PVC, Nylon,
Cotton
Branched
◦ Low Density
- Polyethylene (LDPE)
Cross-linked
◦ Rubber
Network
◦ Kevlar, Epoxy

5.  Biodegradable polymers are defined as polymers
comprised of monomers linked to one another through
functional groups and have unstable links in the
backbone.
 They are broken down into biologically acceptable
molecules that are metabolized and removed from the
body via normal metabolic pathways.

6.  They slowly disappear from the site of
administration in response to a chemical
reaction such as hydrolysis.

7. Ideal characteristics of Biodegradable
polymer:-
They should be biocompatible-(shape, surface, and
leachable)
They should be bio absorbable-(degradability profile,
reabsorption of degradation products.)
They should be bi functional-(physical, mechanical and
biological).
They should be stable-(processing, sterilization and
storage).

8. Biodegradable polymers can be
classified in two on the basis of their
sources:
•Natural polymers:
 Proteins: Example: Albumin, Collagen, Gelatin etc.
 Polysaccharides: Example: Sodium alginate, Chitin,
Chitosan, Cellulose, Dextran, Insulin, Starch etc.
•Synthetic polymers:
 Aliphatic polyesters: Example: Poly-Glycolic Acid (PGA),
Poly Lactic Acid (PLA), Poly-Hydroxy Butyrate (PHB), Poly-β-
Malic Acid (PMA) etc.
 Poly Phospho Esters
 Poly Anhydrides
 Poly Phosphazenes
 Pseudo Amino Acids
 Poly Ortho Esters

9. The use of natural biodegradable polymers to deliver drugs
continues to be an area of active research despite the advent
of synthetic biodegradable polymers.
Natural polymers remain attractive primarily because,
They are an attractive class of biodegradable polymers.
They are derived from natural sources.
They are easily available.
They are relatively cheap.
They qualify for a number of chemical modifications.
They can be a protein or a polysaccharide in chemical
origin.

10. Most attractive class of polymers.
Biocompatible and versatile in terms of physical,
chemical and biological properties.
 Stability of the polymer can be increased as they are
chemically synthesized.

11.  Polymer degradation is a change in the properties – tensile strength,
colour, shape, etc of a polymer or polymer based product under the
influence of one or more environmental factors such as heat, light or
chemicals.
 The term 'biodegradation' is limited to the description of chemical
processes (chemical changes that alter either the molecular weight or
solubility of the polymer)
 ‘Bioerosion' may be restricted to refer to physical processes that
results in weight loss of a polymer device with respect to time.

12. • BIODEGRADATION
HYDROLYSIS
SURFACE EROSION
ENZYMATIC
DEGRADATION COMBINATION
BULK EROSION

13. 1) Bulk erosion
 Degradation takes place throughout
the whole of the sample.
 Ingress of water is faster than the
rate of degradation
Eg : Polylactic acid (PLA)
Polyglycolic acid (PGA)
2) Surface erosion
◦ Sample is eroded from the surface.
◦ Mass loss is faster than the ingress of water
into the bulk
Eg:Polyanhydrides
polyorthoesters

14. CLEAVAGE OF CROSSLINKS TRANSFORMATION OF SIDE CHAINS
CLEAVAGE OF BACKBONE
Chemical or enzymatic degradation – It is mediated by water,
enzymes, microorganisms.

15.  Morphological factors
• Shape & size
• Variation of diffusion coefficient and mechanical stresses
 Chemical factors
• Chemical structure & composition
• Presence of ionic group and configuration structure
• Molecular weight and presence of low molecular weight compounds
 Physical factors
• Processing condition
• Sterilization process

16. • Localized delivery of drug
• Sustained delivery of drug
• Stabilization of drug
• Decrease in dosing frequency
• Reduce side effects
• Improved patient compliance
• Controllable degradation rate

17.  Polymer system for gene therapy.
 Biodegradable polymer for ocular, tissue engineering,
vascular, orthopedic, skin adhesive & surgical glues.
 Bio degradable drug system for therapeutic agents such
as anti tumor, antipsychotic agent, anti-inflammatory
agent.
 Many biomaterials, especially heart valve replacements
and blood vessels, are made of polymers like Dacron,
Teflon and polyurethane.

18.  Biopol
. Polycaprolactone
 Polylactic Acids
 Polyglycolic Acids
 Polydioxane