Plastic Materials for Medical devices
July 2015
Table of Contents
Abstract 1
1. Medical Plastics Market overview 1
2. Polymer materials 2
3. Healthcare Domain requirements 3
3.1 Sterilization compatibility 4
3.2 Biocompatibility 5
3.3 Benefits of Medical Polymer knowledge 6
4. Summary 6
5. How will your use case bring value to IGATE business/vertical 6
6. References 6
7. About the Authors 6
Abstract
Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics; good Processability, balanced engineering properties and optimum cost led its entry into medical
Modern healthcare would be impossible without plastics medical products we tend to take for granted: disposable
Syringes, intravenous blood bags and heart valves, etc. Plastics packaging is particularly suitable for medical applications, thanks to their exceptional barrier properties, light weight, low cost, durability, transparency and compatibility with other materials.
Figure 4: Polymer Families
3. Healthcare domain requirements
Medical devices demands for specific properties in addition to general properties like mechanical & electrical. Sterilization and biocompatibility plays prime role in selection healthcare polymer. Material knowledge and its selection process is the key step in product design and development process. Following are few design requirements enlisted for medical devices design:
Sterilization
Biocompatibility
Good chemical resistance
Colour
Texture
Reusable / Disposable
Duration of contact
Mechanical
Plastics react differently to various sterilization methods. The most common sterilization methods are radiation (gamma/e-beam), chemical (ETO) and autoclave (steam). The majority of thermoplastic polymers can withstand exposure to toxic Ethylene oxide (ETO) without significant changes to their properties or colour during sterilization.
However, plastics subjected to radiation sterilization will be affected, and it may change the mechanical properties of the material such as tensile strength, impact strength and elongation by chain scission or cross-linking. It is also important to note that multiple exposures to radiation are cumulative. In terms of mechanical performance, PC is generally resistant to radiation, but it will discolor with radiation exposure. The key to selection is highly resistant plastics which can perform well after sterilization. Figure 6: sterilization methods
Table 1: Medical polymers resistant for radiation process
# Radiation process Resistant Materials
1 E-beam sterilization Styrenic, Olefins, PC, Acrylics, Blends
2 Gamma sterilization PC, acrylics, sulphides,
There are three risk levels (low, medium and high) associated with sterile compounding. CSPs are assigned a risk level based on the probability of contaminating the preparation during compounding with microbial contaminants e.g. spores or endotoxins and chemical and physical contaminants e.g. skin particles from staff or broken glass. Once a CSP is classified, a licensed healthcare professional overseeing the sterile compounding can then decide upon the most suitable procedure and environmental quality of the facility which are necessary for preparing the CSP. The risk levels apply to the quality of the CSP d...
Alumina and zirconia ceramics have been widely used in orthopaedic hip replacements for the past 30 years. The advantage of using these was lower wear rates than those observed using polymers and metals. Because of the ionic bonds and chemical stability of ceramics, they are relatively biocompatible and therefore more preferable to use than metals and polymers. Alumina is most commonly used as a femoral head component instead of a metal in a hip prosthesis because this would reduce the polyethylene wear that is generated. Alumina is a desirable biomaterial to use in hard tissue implants because of characteristics like excellent wear resistance, high hardness, bio inert, low abrasion rate and good frictional behaviour. Furthermore, it has excellent surface finish as well as high fatigue streng...
such as those that give off radiation as well as x-ray machines, and medical devices. The FDA is
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
Since human recognize the material, biomaterials have had initial development. As early as 3500 BC, the ancient Egyptians used sutures made of cotton fiber or horse hair, and in 16th century gold plate was used to repair jaw bone and ceramic materials were used to make dedendum, and so on. With the development of medicine and materials science, especially the success of the research and development of new materials, such as the rapid development of polymer materials in the 1940s provides a great opportunity for the research and application of biomaterials. It could be said that in addition to the brain and most
In addition, the plastics have shown to generate more damage to the environment in the long-term than any other sources of energy. So, it becomes our responsibility to preserve the environment creating mass awareness. The practice of bio-plastics are an environment friendly method, which doesn’t use the landfills while recycling and deposition, but it is also not that convenient method because the cost of manufacturing bio-plastics are much higher than ordinary method. This directly indicates that the cost of minimizing the waste, the cost of human health and environmental pollution is much higher than the production of
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
There are numerous factors which can affect dimensions of subsequent casts on repetitive pouring. These include the process of polymerization (7), temperature (1), and material used to fabricate the replica or working cast (1). Although, PVS impression materials have demonstrated superior dimensional stability when compared with other elastomeric materials due to no releasing any by-products (8), it had been reported that the dimensional accuracy of a material is time dependent. A material may be highly dimensionally accurate soon after its initial polymerization but less accurate after the storage for a period of time (9). On the other hand, PVS impression materials have chosen as the impression material in many clinical situations because they possess excellent physical properties and handling characteristics
The only way to ensure that sterilization has occurred is to use the biological monitoring methods. This is because these are the only tests done which show whether or not actual microbial life has been killed. Biological methods are the only ones which are recommended by the CDC (Centers for Disease Control and Prevention), the AAMI (Association for the Advancement of Medical Instrumentation), the AMA (American Medical Association), OSHA, and OSAP (Office Safety and Asepsis Procedures Foundation)
... converting plastic waste into useful products are being affected by pollution; this contamination is found within containers where plastics are collected. But the same risk of pollution carries downside consequences in which workers and people responsible for cleaning and disinfecting the plastic materials are not doing the best to eliminate plastic waste, and to disinfect the infected bacteria and microorganisms from the atmosphere and environment. Organizations from China and India are the largest in the world, they collect and purchase used plastic from United States, Europe, Asia and Latin America (Minguez 2013). These companies do not bother to sanitize the products before the recycling process; for this reason the planet earth is getting a worse environmental condition, and it is destroying lives of living beings, and natural resources as well (Uddin 2014).
Plastic makes our lives easier, but they will make more difficult through the damage, they cause to our air quality, soil, and water. We need to change our habit of using the plastic and be part of the solution to make this world better place.
Over the course of the past 60 years, an increasing amount of the current population is using plastic and reusable products to try and reduce the amount of waste that is being thrown away. Bisphenol A (BPA) is used to manufacture polycarbonate #7 plastic which have help strengthen plastic bottles, food containers and epoxy resins (University of Minnesota, 2008). BPA is used in a range of products from every day plastic beverage containers and plastic dinnerware, to compact disks, impact-resistant safety equipment, automobile parts, and toys (Centers for Disease Control and Prevention, 2013). The CDC (2013) also states that BPA epoxy resins are used in the protective linings of food cans, in dental sealants, and in other products (Centers for Disease Control and Prevention, 2013).
It would be difficult to imagine the modern world without unreinforced and reinforced plastics. Today they are an integral part of everyone's life-style, with products varying from commonplace domestic to sophisticated scientific products. In fact, many of the technical wonders we take for granted would be impossible without these versatile and economical materials.
Plastic is used in everything from food containers, to shoe soles, plastic bottles, baby bottles, sippy cups, medical devices, dental sealants, water bottles, specific hard plastics, and reusable water bottles. Additionally, inside these packaged items is a synthetic compound lining that has been used to reinforce these plastics and cans for more than 40 years (Shaw).
that make thousands of types of plastics. Ink pens, car parts and plastic bags are all made