Biodegradable Polymers
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Transcript of Biodegradable Polymers
Biodegradable Polymeric Delivery System
Presented By:Presented By:
Sunil Kamboj
Roll No: 1211533
DEPARTMENT OF CHEMICAL ENGINEERING
JMIT, Radaur- 135133
A large number of the carriers have been designed for delivery of proteins and peptides via liposome, niosome, polymeric nanoparticles, solid lipid nanoparticles etc.
Polymer based carriers have taken much attention of the scientific community for safe and effective delivery of proteins.
Biodegradable polymers is used through slight modifications of their structures.
Biodegradable polymers have a great applications in pharmaceutical, medical and biomedical engineering.
Biodegradable polymers are not limited to release of drugs, peptides or proteins but are also extended to medical devices and wound dressing.
Polymer?• Large molecule composed of a number of sub-units
- Natural e.g. alginates,
- synthetic e.g. poly(HMPA)
- Function governed by number and arrangement of constitutional repeat units e.g. –[A-]n, -[A-B-]n, -[A-A] n-[B-B] m , --A-A-B-A-B-B-A-
• How are they made?- Processing of natural products – alginates from seaweeds, celluloses
from plants
- Synthesis from chemical feedstocks – poly(olefins), nylons, poly(esters)
• How can they help?- Protection of therapeutic compound during passage through body, as
encapsulant or carrier.
- Mediator or activator of controlled release
CHARACTERISTICS OF IDEAL POLYMER
Should be inert and compatible with the environment.
Should be non-toxic.Should be easily administered.Should be easy and inexpensive to
fabricate.Should have good mechanical strength.
Criteria Followed In Polymer SelectionIt must be soluble and easy to synthesize;
must have a finite molecular wt.Should provide drug attachment and
release sites for drug polymer linkages.Should be compatible with biological
environment, i.e. non-toxic and non-antigenic.
Should be biodegradable or be eliminated from body after its function is over.
Biodegradable polymers- Polymer degrades in vivo to release the drug
- Simple release mechanism, but difficult to obtain fine control over degradation
- Does not invoke an inflammatory or toxic response.
- It is metabolized in the body after fulfilling its purpose, leaving no trace
• Examples in use- Resomer (PLGA)
- Vicryl (PLGA)
• Common biodegradable polymers
- Poly(lactide-co-glycolide) (PLGA)
- Poly(hydroxybutyrate-co valerate) (Biopol)
List of Biodegradable Polymers used in Drug Delivery
Natural polymers
Protein-based polymers Collagen, albumin, gelatin
Polysaccharides Agarose, alginate, carrageenan,hyaluronic acid, dextran, chitosan,Cyclodextrins
Synthetic polymers
Polyesters Poly(lactic acid), poly(glycolic acid),poly(hydroxy butyrate), poly(ε- caprolactone),poly(α-malic acid), poly(dioxanones)Polyesters
Polyanhydrides Poly(sebacic acid), poly(adipic acid),
Continues......
Polyamides Poly(imino carbonates), polyamino acids
Phosphorous-based polymers
Polyphosphates, polyphosphonates, polyphosphazenes
Others Poly(cyano acrylates), polyurethanes, polyorthoesters,polydihydropyrans, polyacetals
Polymeric DDS devicesParticulate systems
NanoparticlesNanocapsulesNanospheres
Microparticles MicrospheresMicrocapsules
Controlled release implies controlled release of drugs from polymer drug delivery systems (DDS)
Type of polymerNon-degradable / Degradable
Type of Design
Reservoir Matrix
Release mechanismsDiffusion / polymer degradation / combination
Controlled Release Systems
Biodegradable Delivery Systems
Drug is physically incorporated (mixed) into a biocompatible polymer matrixDrug is protected by the polymer
Drug migrates from the polymer to the bodyDrug is released in a controlled manner
After all drug is released, surgical removal of the polymer is not necessaryPolymer contains labile bonds
t = 0 t = n
polymer
drug
Mechanism of BiodegradationA. Hydrolytic Degradation : Breakdown of polymer by water by cleaving
long chain into monomeric acids. This is done by two ways :
Bulk eroding polymerse.g. Polylactic acid (PLA)
Polyglycolic acid (PGA) Surface Eroding Polymers
e.g. PolyanhydridesB. Enzymatic Degradation : Exact mechanism is not known but may be
due to lysis of long polymer chain by attaching to it.
Drug delivery from (a) bulk-eroding and (b) surface-eroding biodegradable systems
Physical incorporation of a drug in a polymer-based delivery systems are an improvement to conventional administration
Drawbacks:Incorporate low percentages of drugHigh potential for drug separation (accidental or
intentional)Drug is released with a burst
Biodegradable Delivery Systems
Plasma drug concentrations proportional to the dose
Traditional drug dosing requires repeated administration
Drug is distributed throughout the body
Maintain therapeutic levels by a single administration
Drug preservation and protection
Localize drug deliveryIncrease patient comfort and
improve compliance
Drug Delivery Systems
Comparison of Controlled Release System Designs
Polymer Non-degradable Degradable
Design Reservoir Matrix Reservoir Matrix
Release √√√ √√√ √√ √√Removal √ √Rupture √ √Low Mw √ √ √ √High Mw √ √ √Duration 5 years 5 years 1-2 years Months
Examples Norplant® Jadelle® CapronorTM Microspheres
References
Neeraj Mishra, Amit Goyal, Kapil Khatri, Bhuvaneshwar Vaidya, Rishi Paliwal, Shivani Rai, Abhinav Mehta, Shailja Tiwari, Shiva Vyas and Suresh Vyas. Biodegradable polymer based particulate carrier(s) for the delivery of proteins and peptides. Anti-Inflammatory and Anti-Allergy Agents in Medicinal Chemistry, 2008, 7: 240-251.•Gemma Vilar, Judit Tulla-Puche and Fernando Albericio. Polymers and drug delivery systems. Current Drug Delivery, 2012, 9: 1-28.•Kumaresh Soppimatha, Tejraj Aminabhavia, Anandrao Kulkarnia and Walter Rudzinski. Biodegradable polymeric nanoparticles as drug delivery devices. Journal of Controlled Release, 2001, 70: 1–20.• Avnesh Kumari, Sudesh Yadav and Subhash Yadav. Biodegradable polymeric nanoparticles based drug delivery systems. Colloids and Surfaces B: Biointerfaces, 2010, 75: 1–18.• Yulia Chernysheva, Valery Babak, Natalia Kildeeva, Franck Boury, Jean Benoit, Nathalie Ubrichd and Philippe Maincent. Effect of the type of hydrophobic polymers on the size of nanoparticles obtained by emulsification solvent evaporation. Mendeleev Communication, 2003, 13(2), 65–67.