The document provides information on biodegradable natural polymers including gelatin, chitosan, hyaluronic acid. It discusses their sources, properties, production processes and applications. Gelatin is derived from collagen through hydrolysis. Chitosan is obtained from chitin found in crustacean shells. Hyaluronic acid is a polysaccharide produced naturally or through fermentation. These natural polymers are biodegradable, biocompatible and used in various pharmaceutical and biomedical applications such as drug delivery, tissue engineering and wound healing.

1. BIODEGRADABLE
NATURAL POLYMERS
Prepared by: (Group B)
Ajay Shah
Bhaskar Shrestha
Eroj Yemi
Manisha Shrestha
Prakriya Shrestha
Rajiv Dangol
Sajan Maharjan
Tripti Amatya

2. Log Book
Discussion on Topic: Tuesday; 14 January, 2014
Internet Survey: Wednesday to Friday; 15 to 17 January, 2014
Work Division: Saturday; 18 January, 2014
S.No Topics
Name
1
Tripti Amatya
2
3
4
5
6
7
8
Introduction
Gelatin
Chitosan
Hyaluronic Acid
Conclusion &
Compilation
Date
Manisha Shrestha
Prakriya Shrestha
Bhaskar Shrestha
Eroj Yemi
Rajiv Dangol
19th to 21nd January
2014
Sajan Maharjan
Ajay Shah
Disscussion and Modification of Assignment: Wednesday to Saturday; 22 to 25 January, 2014
Preparation of Presentation: Friday to Sunday; 24-26th January, 2014

3. INTRODUCTION

Polymer Definition

Also known as macro-molecules.

4. Biodegradation
Biodegradation is the process of converting polymer material into
harmless, simple, gaseous products by the action of enzymes, microorganisms and water.
Biodegradable Polymer
Biodegradable polymers degrade as a result of natural biological
processes, eliminating the need to create a disposal system which can
cause harm to our environment.
Mechanism Of Biodegradable Polymers
BIODEGRADATION
ENZYMATIC
DEGRADATION
BULK EROSION
COMBINATION
HYDROLYSIS
SURFACE EROSION

5. ENZYMATIC
DEGRADATION

6. Need for Biodegradable polymer
 Do not require a second surgery for removal
 Avoid stress shielding
 Offer tremendous potential as the basis for controlled drug
delivery
Mechanical Strength
BONE+PLATE
Degradable Polymer
Plate
PLATE
BONE
Time

7. NATURAL POLYMERS
These are the polymers obtained from natural resources,
and are generally non-toxic.
Natural polymers are formed in nature during the growth
cycles of all organisms.
NATURAL POLYMERS
PROTEINS
Polysaccharides
Eg: COLLAGEN
ALBUMIN
FIBRIN
Eg : DEXTRAN
CHITOSAN
STARCH
ADVANTAGES :
1) Readily & Abundantly Available.
2) Comparatively Inexpensive.
3) Non toxic products.
4) Can be modified to get semi synthetic forms.

8. Classification of Natural biodegradable polymers
(Based on Origin)
Plant
Polysaccharides
Eg: Cellulose, Starch,
Alginate
Animal
Proteins
Eg:
Collagen
(Gelatin),
Albumin
Polysaccharide
s
Eg: Chitin
(Chitosan),
Hyaluronate
Microbes
Polyesters
Eg: Poly(3hydroxylalko
nate)
Polysaccharides
Eg: Hyaluronate

9. CHITOSAN: INTRODUCTION



Chitin is a macromolecule found in the shells
of crabs, lobsters, shrimps and insects
Chitosan is obtained by partial deacetylation
of chitin.
Chitin is insoluble in its native form but
chitosan, the partly deacetylated form, is
water soluble.

10. CHEMISTRY

linear co-polymer of β(1-4) linked
glucosamine and N-acetyl-D-glucosamine.

11. EXTRACTION OF CHITOSAN
Crustacean shells
(containing chitin)
Dil. NaOH Deproteinization
Dil. HCl
Demineralization
0.5% KMnO4 and
oxalic acid
Deacetylation
(chitosan)
Hot Conc. NaOH
(40-50%)
De colorization

12. PHYSIOCHEMICAL PROPERTIES






Odorless, white or creamy-white powder
Chelates many transitional metal ions
Highly basic polysacharides
in acidic pH, it gets solubilized due to protonation of
free amino groups and the resultant soluble
polysaccharide is positively charged.
hydrophilic in nature thereby it has the ability to form
gels at acidic pH.
Degraded by lysozyme to it’s by products
glucosamine and n-acetyl glucosamine

13. APPLICATION

Ocular delivery:



Colon drug delivery:


making contact lens- optical clarity, sufficient optical
correction, gas permeability, particularly towards oxygen,
wettability and immunological compatibility.
antimicrobial and wound healing properties of chitosan
along with an excellent film capability make chitosan
suitable for development of ocular bandage lenses.
Degraded by microflora present in human colon which
supports colon drug delivery
Coating material:

Good film forming property and mucoadhesive property

14. 
Mucosal delivery:


Transdermal drug delivery:


Studies on propranolol hydrochloride (prop-HCl)
delivery systems using various chitosan membranes
with different crosslink densities as drug release
controlling membranes and chitosan gel as the drug
reservoir have been performed.
Gene Delivery:


Chitosan gets protonated in acidic solution, so it binds
strongly to negatively charged cell surface making it
useful to formulate bioadhesive dosage forms.
Chitosans, typically isolated from the shell of shrimp,
has the ability to react with DNA and compact it to
produce a nanoparticle. Such nanoparticles are more
readily taken up by cells.
Others: nano band- aid,cosmetics, etc.

15. HYALURONIC ACID:INTRODUCTION




Carbohydrate polyanionic
mucopolysacharide, occurring naturally in all
living organisms.
Can be several thousands of sugar long
One of most hydrophiic molecules, also
known as natural moisturizer
Generally found in sodium salt form i.e. as
sodium hyaluronate

16. BIOSYNTHESIS OF HA IN BACILLUS
SUBTILIS
Pentose phosphate
pathway
Glycolysis
UDP-N-acetylglucosamine
UDP- glucoronic acid
Hyaluronan
synthase
UDP
HYALURONIC ACID
UDP
•HA is naturally synthesized from addition of glucoronic acid
and N-acetylglucosamine to growing chain using their activated
nucleotide sugars. Hyaluronan synthase is the enzyme
responsible.

17. STRUCTURE AND CHEMISTRY



Polysaccharide made up of largely repeating
disaccharide units
The alternating disaccharide units are linked by
(1→4) inter glycosidic linkage.
Chains consist upto 30,000 repeating units so it has
high molecular weight range (1000 to 10,000,000
Da).

18. PROPERTIES






Biodegradable, biocompatible, non-toxic, nonimmunogenic, non-inflammatory, linear chain
polysaccharide
very hydrophilic; it adsorbs water making it
hygroscopic
readily soluble in water, and produces a gel
Its viscous solutions have most unusual rheological
properties (pseudoplasticity) and are exceedingly
lubricious
To improve the mechanical properties and control the
degradation rate, HA can be chemically modified or
crosslinked to form a hydrogel
of the gel is dependent upon a number of factors
including the length of the chain, cross-linking, pH

19. APPLICATION


They are used in the preparation of gels for
delivery of drugs to eye and installation into
other cavities.
Microparticulate HA carrier:
 Sustained-release
formulations (eg: protein drugs)
have been developed using spray-dried HA
microparticles which act as a protein reservoir
 Also protects the drugs from denaturation and
increases their bioactivity

Ocular drug delivery:
 Its
viscosity and pseudoplastic behavior which provide
mucoadhesive property can increase the ocular
residence time

20. 
Cell targetting:
 The
expression of CD-44 (cluster determinant 44)
and RHAMM (receptor for hyaluronate-mediated
motility) receptors by various tumour cells, which
are endogenous ligands for HA, makes this a good
candidate for drug targeting to cancer cells

Nasal delivery:
A
nanocarrier composed of hyaluronic acid(HA)
and chitosan(CH) was reported to encapsulate
bovine serum albumin (BSA) and cyclosporine A
for the nasal delivery of macromolecules

Topical drug delivery:
 Surface
hydration and film formation enhance the
permeability of the skin to topical drugs also
promotes drug retention and localization in the
epidermis

21. HA has been used in tissue engineering for
the cartilage replacement in the joints
 Used in cosmetics, skin care system, as anti
ageing therapy (antioxidant nature)


22. GELATIN-INTRODUCTION
•
•
•
Gelatin is a natural water soluble functional polymer
(protein) that is derived by partial hydrolysis of collagen
(chief protein component in skin, bones and white
connective tissues of the animal body).
It is commonly used for pharmaceutical and medical
applications because of its biodegradability and
biocompatibility in physiological environments.
Gelatin does not occur free in nature, and derived from
chief protein component in skin, bones, hides, and white
connective tissues of the animal body is classified as a
derived protein

23. GELATIN-TYPES
Gelatin derived from an acid-treated precursor is
known as Type A and gelatin derived from an
alkali-treated process is known as Type B.
 Results in a difference in isoelectric points, being
7 – 9 for gelatin type A and 4 – 5 for gelatin type
B.


24. FEATURES OF GELATIN


Characteristic features of gelatin are the high content of
the amino acids glycine, proline (mainly as
hydroxyproline) and alanine.
Gelatin molecules contain repeating sequences of
glycine, proline and alanine amino acid triplets, which
are responsible for the triple helical structure of gelatin.

25. STRUCTURE OF GELATIN
The chemical structure of gelatin is what makes gelatin
water soluble; form digestible gels and films that are strong,
flexible, and transparent; and form a positive binding action
that is useful in food processing,pharmaceuticals,
photography,and paper production.

26. MFG OF GELATIN

27. PHYSICAL PROPERTIES




Tasteless and odorless
Vitreous, brittle solid, yellow colored
Moisture content: 8-13% ; Relative density of: 1.3-1.4
Formation of thermo-reversible gels in water: When
gelatin granules are soaked in cold water they hydrate
into discrete, swollen particles. On being warmed, these
swollen particles dissolve to form a solution.

28. CHEMICAL PROPERTIES





Soluble in aqueous solutions of polyhydric alcohols such as glycerol and
propylene glycol.
Insoluble in less polar organic solvents such as benzene, acetone,
primary alcohols and dimethylformamide.
Gelatin stored in air-tight containers at room temperature remains
unchanged for long periods of time. When dry gelatin is heated above
45 C in air at relatively high humidity (above 60% RH) it gradually
loses its ability to swell and dissolve.
Sterile solutions of gelatin when stored cold are stable indefinitely; but
at elevated temperatures the solutions are susceptible to hydrolysis.
Gelatin is composed of 50.5% carbon, 6.8% hydrogen, 17% nitrogen
and 25.2% oxygen. It gives typical protein reactions and is hydrolyzed
by most proteolytic enzymes to yield its peptide or amino acid
components.

29. APPLICATION OF GELATIN IN
PHARMACEUTICAL FORMULATION
AND DRUG DELIVERY










Two-Piece Hard Capsules
Soft Elastic Gelatin Capsules
As a binder in Tablet
Tablet Coating
Suppositories
Gelatin Emulsions
Microencapsulation
Source of essential amino acids
Absorbable Gelatin Sponge
Gelatin as Nanoparticle.

30. CONCLUSION





Biodegradable polymers have received much more attention in
the last decades due their potential applications in the field of
pharmaceuticals.
Biodegradable polymers have been researched, but polymers
based on renewable sources (especially on starch) are most
desirable.
It provides a drug at a constant controlled rate owes a prescribed
period of time; cell targeting, colon targeting and nasal drug
delivery system and also assist in gene therapy.
It would degrade into nontoxic, absorbable subunits which would
be subsequently metabolized and removed from the body.
Recently different studies have been reported concerning the use
of degradable polymers, especially with starch and aliphatic
polyesters.

31. Reference
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Handbook.
 Djagny B. K.,Wang Z. , Xu S. ,Gelatin: A Valuable Protein for Food and
Pharmaceutical Industries: Review,Critical Reviews in Food Science and Nutrition,
41(6):481–492 (2001).
 Wiley J. & Sons, Encyclopedia of Polymer Science and Technology.
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 Ames, W. M., The Conversion of Collagen to Gelatin and their Molecular
Structures, J. Sci. Food Agric.,1952; 3: 454–463.
 R. T. Jones, in K. Ridgway, ed., Hard Capsules Development and Technology, The
Pharmaceutical Press, London, 1987, pp. 41–42.
 Remington’s Pharmaceutical Science, 1985. 17th edition, Mach Publishing
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 The United States Pharmacopeia XXII (USP XXII–NFXVII), the United States
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33. THANK YOU