POLYVINYL CHLORIDE AS A BIOMATERIAL
this slide shares the use of PVC as a bio material particularly in medical applications .its synthesis ,plasticizers . properties,advantages and disadvantages
Published on: Mar 4, 2016
Transcripts - POLYVINYL CHLORIDE AS A BIOMATERIAL
POLY VINYLCHLORIDE(PVC) as a Biomaterial
2nd M.sc biopolymer science
• The most widely used thermoplastic material in the
medical device industry is PVC.
• PVC was originally developed to replace the rubber and
glass that was historically used to make flexible tubing
• PVC is the dominant material used for the storage of IV
fluids, dialysis solutions, as well as blood and blood
• Studies suggest that 25% of all plastics used in hospital
environments are PVC-based
PREPARATION OF VINYL CHLORIDE
1) Laboratory preparation
2) Commercial preparation
• Bulk polymerization
• Suspension polymerizations
• Emulsion polymerization
Properties and advantages
• It can be sterilized with steam withstanding
temperatures as low as -40°C and as high as 121°C.
• PVC can also be sterilized using an ETO (Ethylene
Oxide) and with a Gamma Irradiation Electron Beam.
• PVC can also be joined together with high frequency
welding thus allowing for a wide variety of container
shapes and numerous types of attachments.
• Commercially available PVC is highly branched and
has low crystallinity. However, high molecular weight
PVC has a more ordered structure, is less linear and
has a higher degree of crystallinity
• Medical products made from PVC are usable inside
the body, easy to sterilize and simple to assemble
into products that do not crack or leak.
Reasons To Use PVC in Medical Applications
• 1) Safety
• Before PVC can be used in medical devices, it must be
thoroughly tested from a toxicological point of view.
• PVC material sterilized in Ethylene Oxide and consequently
Re-sterilized in EO show NO TOXICITY
• 2) Chemical Stability
• chemically stable, inert
• Alkali resistant ,non pyrogenic odorless and tasteless
• 3) Clarity and Transparency
• Products made from PVC can be formulated with excellent
transparency to allow for continual monitoring of fluid flow. It
can even be colour coded to virtually any colour needed.
• 4) Biocompatibility
• When plastics are used in direct contact with a patient’s tissue
or blood, a high degree of compatibility is required between
the tissue/blood and the material. The significance of this
property increases with the time over which plastic is in
contact with the tissue or blood.
• 5) Flexibility, Durability and Dependability
• Not only does PVC offer the flexibility necessary for
applications such as blood bags and IV containers, but it
can also be relied upon for its strength and durability,
even under changing temperatures and conditions. PVC
can also be easily extruded to make IV tubing,
thermoformed to make 'blister' packaging or blow
moulding to make hollow rigid containers. This versatility
is a major reason why PVC is the material of choice for
medical product and packaging designers.
• 6) Low Cost
• PVC accounts for almost one third of the cost of
medical plastic today, hence its low cost has a
profound effect on maintaining the lower costs of
medical plastics generally. A switch to another
plastic could cost the healthcare industry hundreds
of millions of dollars per year.
• 7) Resistance to Chemical Stress Cracking
• Stress cracking is one of the most common symptoms of
polymer damage. Stress causes the secondary linkages
between polymers resulting in little fractures, like you
may have seen in a plastic cup that didn’t survive the
dishwasher. PVC's resilience helps assure that medical
products function consistently for extended use and in
Plasticizers in medical applications
• Most medical devices made from PVC use
plasticizers to give the flexibility that makes the
material so appropriate for use. The main plasticizer
types are known as phthalates. These are a group of
colorless, odorless and, in the presence of oxygen,
readily biodegradable liquids.
• One of the most important phthalates by tonnage is
DEHP[Di(2-ethylhexyl) phthalate], which is currently
the only listed plasticizer recommended by the
European Pharmacopoeia as the substance of choice
for softening disposable medical items, blood bags
• major beneficial consequences of plasticizers
migration in that some plasticizers (DEHP and BTHC)
actually contribute to enhanced red cell survival and
therefore increased shelf-life for whole blood. This is
explained by the fact that the plasticizer interacts
and stabilizes the red cell membrane.
• DEHP can leach out into solutions that come into
contact with the plastic. The amount of DEHP
leaching out depends on the temperature
Alternatives for medical device
• Trioctyl trimellitate (TOTM)
• Butryl trihexyl citrate (BHTC)
• Di isonoyl cyclohexane-1,2-dicarboxylate(DINCH)
• Bis(2-ethylhexyl) adipate
• Ca- Zn stabilizers
Solution packagingdialysis tube
Urine bag Gas mask
thank you !