4. Definition
• The compounds having high molecular masses and
formed by monomers are termed polymers.
• The term polymer is derived from the Greek words:
Poly means (many)
Meros means (unit) or (parts)
• Polymers are very large molecules made when
hundreds of monomers join together to from long
chains.
5. Polymerisation: The process by which the monomer molecules are linked to from a big
polymer molecule is called “polymerisation”
The first polymer-drug conjugates appeared around 1955, being mescaline -N-
vinylpyrolidine conjugate one of the first.
Herman Staudinger, who received the Nobel Prize in Chemistry in 1953, coined the
term “macromolecule” in 1922 and used it in reference to polymers.
In 1994 , the first synthetic polymer-drug conjugate designed to treat cancer was clinically
tested.
In the 2000s, two polymer-protein conjugates, PEG-interferon-a(an antiviral drug intended
to treat chronic hepatitis C and hepatitis B) ans PEG granulocyte colony-stimulating factor).
Were placed in the market and five years later the first therapeutic nanoparticles(albumin-
entrapped paclitaxel) was approved as a treatment for metastatic breast cancer.
6. • Due to their distinctive nature, polymer are used in
pharmaceutical industries.
• Polymers are pharmaceutically used in tablets as binders, in
liquids suspensions and emulsions as flow controlling
agents, to cover the unpleasant taste of drug as film coating
agents, and also as stabilisers and protective agents
• Polymers are broadly used in day-to-day life
• Important advancements have been made in the
development of several drug delivery devices using
polymers
7.
8. Classification of Polymer
1. Natural
polymers
Based on origin of
source
2. Semi-
synthetic
3. Synthetic
polymer
1. Linear polymers
Based on structure
2. Branched chain
polymers
3. Cross-linked
polymers
1. Non-Biodegradable
Polymer
Based on the
degradability
2. Biodegradable
Polymer
Based on mode of
polymerisation
1. Addition
polymers
2. Condensation
polymers
9. Based on origin of source
• Natural polymers: These are derived from natural sources and can be
polysaccharides and protein in chemical nature.
For example: Albumin, Cellulose, Starch, Rubber, Wool.
• Semi-synthetic polymers: These types of polymers are derived from
naturally occurring polymers by means of chemical modifications.
• Vulcanized rubber is used in making tyres as the process of vulcanization
increases the mechanical strength of natural rubber.
For e.g. Vulcanized rubber, Gun cotton, Cellulose diacetate, HPMC,
etc.
10. • Synthetic polymers: Synthetic polymers are of artificial origin
which consist of fibers.
• This is the polymer, which was prepared by Laboratory is known as
Synthetic Polymer
• For example: Buna-S, Buna-R, Nylon, Polythene, Polyester
11. Based on structure
• Linear polymers: The smallest repeating unit
arranged in straight line path is known as Linear
polymer.
For example: PVC
• Branched chain polymers: Contain linear chains
having some branches
For example: low density polymer,
Polyethylene, HPLD polyethylene
12. • Cross linked chain polymers: In this type, all molecules are
chemically bonded together, forming a three-dimensional network
• The bonding is usually covalent but other types such as; ionic bond is
also possible
• Cross-linked polymers are produced from linear and branched
polymers or directly from chemical precursor.
For ex. Natural rubber, polyacrylamide gels, epoxies, alkyd resins,
etc.
13. Based on the degradability
• Non-Biodegradable Polymers: These polymers do not undergo
natural degradation in the body.
Polyethene Vinyl Acetate (PVA), Polyethene Vinyl Chloride (PVC),
Polydimethyl Siloxam (PDS), Polyetiner Urethane (PEU), Ethyl Cellulose (EC),
Cellulose Acetate (CA), and polyethylene are the examples of non-
biodegradable polymers.
• Biodegradable Polymers: These polymers undergo natural
degradation in the body.
Polycaprolactone (PCL), Polylactic Acid (PLA), Polyglycolic Acid (PGA),
Poly(Lactic-co-Glycolic) Acid (PLGA), etc. are the examples of biodegradable
polymers.
14. Properties
• Many materials are used for controlling the release of drugs and other active
agente.
• Initially the earliest of these polymers were designed for other non-biological
and were chosen due to their desirable physical properties. Some examples are:
1) Poly(urethanes) for elasticity.
2) Poly(siloxanes) or silicones for insulating ability.
3) Poly(methyl methacrylate) for physical strength and transparency.
4) Poly(vinyl alcohol) for hydrophilicity and strength.
5) Poly(vinyl pyrrolidone) for suspension capabilities
Low Density
Good corrosion resistance
Economical
15. An Ideal polymer should have the following properties.
• 1) It should be inert and compatible with the environment.
• 2) It should be non-toxic.
• 3) It should be easy to administer.
• 4) Its fabrication should be easy and inexpensive.
• 5) It should have a good mechanical strength.
16. Advantage
It delivers drug at a constant rate of controlled release for a prescribed time period.
The carrier of polymer degrades into non-toxic and absorbable sub-units that get
metabolised lately.
The system is biocompatible, does not exhibit dose dumping at any time period, and the
polymer retains its properties until after drug depletion.
Biodegradable systems remove the need for surgical removal of implanted device after
drug depletion.
They breakdown into biologically acceptable molecules which metabolised and
eliminated from the body via normal metabolic pathways.
17. Localized delivery of drug Presence of substances that may be issued
in the body [monomers (toxic), catalysts, additives] after Degradation
Sustained delivery of drug
Stabilization of drug
A "burst effect" or high initial drug release soon after administration
is typical of Decrease in dosing frequency Reduce side effects most
system.
Improved patient compliance
18. Application
• Immediate Release Dosage forms
Tablet
Capsule
• Modified Release Dosage Forms
• Controlled Release Dosage Forms
Reservoir systems
matrix systems
Swelling controlled Release systems
Biodegradable systems
• Extended Release Dosage Forms
19. Polymer Application
Polyethylene oxide Cosmetic Pharmaceuticals
Polyethylene glycol Swelling agent
PVP Tablet granulation
Polyvinyl alcohol Tablet binder and coationg
Ethyl cellulose Sustained release system
Carboxy methyl cellulose Super disintegrant
HPMC Coating and binder