introduction what is polymer? classification on the basis of various types natural polymer ...

Introduction What is polymer? Classification on the basis of various types Natural polymer Biodegradable polymer Characteristics of ideal modified polymer Advantages Disadvantages Application Conclusion Reference

Polymers are used extensively in our daily routine life. In pharmaceutical preparations also they have several applications.

E.g. In mfg of bottles, Syringes, Vials, and also in drug formulation.

Polymer :Polymer word is derived from Greek roots "Poly" meaning many and "Meros" meaning parts. Defination : Polymers are long chain organic molecules assembled from many smaller monomers called as polymer.

Copolymer : Polymers formed from two or more different monomers are called as copolymers. - [A – B – A – B – A – B] –Homo polymer : Polymers formed from bonding of identical monomers are called as homopolymers. - [A – A – A – A – A] -

1. Biodegradable Polymers: E.g. Polylactic acid, Polyglycolic acid.

2. Non- Biodegradable Polymer : E.g. Polyvinyl chloride, Ethyl cellulose.

Biodegradable polymers: Biodegradable polymers degrade within the body as a result of natural biological processes, eliminating the need to remove a drug delivery system after release of the active agent has been completed. E.g. Polyglycolic acid, poly capronolactone etc.

Classification of Biodegradable polymer

1) Natural Biodegradable Polymers. E.g. amber, wool, silk.

2) Synthetic Biodegradable Polymers. E.g. synthetic rubber, nylon.

1.Natural Polymers:- They are natural products of living organisms,

easily available, relatively inexpensive and capable of chemical modifications.e.g. collagen, albumin etc.

2.Synthetic Polymers:- They are manmade, prepared in laboratories

or industries from chemical substances.e.g. Polyesters, Polyanhyrides, polyamide etc.

• Natural polymers remains the primary choice of formulator because, - They are natural products of living organism - Readily available - Relatively inexpensive - Capable of chemical modification

1) Proteins :- Collagen : Found from animal tissue.

Used in absorbable sutures, sponge wound dressing, as drug delivery vehicles.

- Albumin : Obtained by fabrication of blood from healthy donor.

Used as carriers in nanocapsules & microspheres.

- Gelatin : A natural water soluble polymer. Used in capsule shells and also as coating material in

microencapsulation.

2.Synthetic biodegradable polymer Synthetic Biodegradable Polymers are preferred more than the natural biodegradable polymers because they are free of immunogenicity & their physicochemical properties are more predictable. e.g. Lactide polymer, poly anhydrides,

polyamides.

Non-biodegradable polymers are those polymers which are not degraded by micro-organisms. Major portion of synthetic polymers are being used as throw away containers and packing materials. E.g. synthetic rubber, polyvinyl chloide

inert and compatible with the environment.

nontoxic.

easily administered.

inexpensive to fabricate.

good mechanical strength.

Readily & Abundantly Available.

Comparatively Inexpensive.

Non toxic products.

Modified to get semi synthetic forms.

•Hazardous manufacturing process.

•Expensive.

•Drug release Limited temperature usability, special grade needed for different applications

•Can be destroyed by flame.

As a thickening agent in suspension and ophthalmic preparationsExample: methyl cellulose.

To form bases in ointments.

In hard and soft capsule gelatin is used.

Gelatin also used as suppository base, as an emulsifying agent and suspending agent.

Tablets : - As binders

- To mask unpleasant taste - For enteric coated tablets

Liquids : - Viscosity enhancers

- For controlling the flowSemisolids :

- In the gel preparation - In ointments

In transdermal Patches: - To treat angina pectoris (Nitro glycerine)

Polymeric system have great potential in drug delivery system. Polymers in various configuration have been extensively studied for their possible biomedical application.

1. Prasad YV, Krishnayya YSR and Satyanarayan S. J. control.Rel.1998; 51:2812. Chourasia MK and Jain SK. Pharmaceutical approaches to colon targeted drug deliverysystem. J. Pharm. Pharmaceutical Sci. 2003;6(1): 33‐663. Wikipedia. (2009). [Online] Available: http://www.wikipedia.com (August, 2009).4. Satturwar P.M., Fulzele S.V., Dorle A.K. Biodegradation and in vivo biocompatibility of rosin: A natural film-forming polymer, AAPS Pharm. Sci. Tech. 2003; 4 : 1-6. 5. Lam K.S., New aspects of natural products in drug discovery, Trends Microbial. 2007-15: 279-897