Polymers

1. POLYMERS
Presented By:
Mr. Pradip F. Sontakke
Assistant professor
Dept. of Pharmaceutics
SHREE SAMBHAJI COLLEGE OF PHARMACY KHADKUT , NANDED.

17. 1. Matrix Systems
Polymers are used to form a matrix that encapsulates the drug. The drug is
dispersed throughout the polymer matrix and is released by diffusion
and/or degradation of the polymer. Common polymers used in matrix
systems include:
Eg Hydroxypropyl methylcellulose (HPMC), Ethylcellulose ,Polyvinyl
alcohol (PVA).
2. Reservoir Systems
In reservoir systems, the drug is surrounded by a polymer membrane that
controls the rate of drug release. The release rate can be adjusted by
modifying the polymer's properties. Typical polymers include:
Eg. Polyurethane,Ethylene-vinyl acetate (EVA),Silicone elastomers
Application of polymers in formulation of controlled release formulation

18. 3. Bio adhesive Systems
Polymers with bio adhesive properties can adhere to biological tissues,
such as the mucosal membranes, enhancing drug absorption and
prolonging residence time. Examples include:
Chitosan ,Carbopol ,Polycarbophil.
4. Hydrogels
Hydrogels are three-dimensional polymer networks that can swell in
water and hold a large amount of water while maintaining their structure.
They are used in CRDDS for their ability to release drugs in a controlled
manner through diffusion and swelling mechanisms. Common hydrogels
include:
Polyethylene glycol (PEG),Polyvinyl alcohol (PVA),Polyacrylamide.

19. 5. Microspheres and Nanoparticles
Polymers are used to form microspheres and nanoparticles that
encapsulate the drug, protecting it from degradation and controlling its
release. These particles can be designed to release the drug over a
prolonged period. Polymers used include:
Polylactic acid (PLA),Polyglycolic acid (PGA),Poly(lactic-co-glycolic
acid) (PLGA)
6. Transdermal Systems
Polymers are used in transdermal patches to control the release of drugs
through the skin. These systems provide a steady release of drugs over an
extended period. Commonly used polymers include:
Polyisobutylene,Polyacrylate,Silicone-based adhesives

20. 7. Osmotic Systems
Polymers are used in osmotic drug delivery systems, where the drug is
released through a semi-permeable membrane driven by osmotic
pressure. Polymers used in these systems include:
Cellulose acetate ,Polyethylene oxide
8. Implantable Systems
Polymers are used to create implantable devices that release drugs over
a long period. These devices can be biodegradable or non-
biodegradable, depending on the application. Examples include:
Polylactic acid (PLA), Poly(lactic-co-glycolic acid)
(PLGA),Polycaprolactone (PCL)

21. 9. In Situ Forming Systems
Certain polymers can form gels or solidify upon contact with body
fluids, creating a depot that releases the drug over time. Polymers used
in these systems include:
Poloxamers
Poly(lactic-co-glycolic acid) (PLGA)
Chitosan