Elastomeric materials, packaging

Corrosion Inhibition. Another important property of antifreeze solutions is the corrosion protection they provide. Most cooling systems contain varied materials of constmction including multiple metals, elastomeric materials, and rigid polymeric materials. The antifreeze chosen must contain corrosion inhibitors that are compatible with all the materials in a system. Additionally, the fluid and its corrosion inhibitor package must be suitable for the operating temperatures and conditions of the system. 

On the other hand, certain applications could not exist without adhesive bonding. Examples of these are the joining of ceramic or elastomeric materials, the joining of very thin substrates, the joining of surface skin to honeycomb, and numerous other applications. There are also certain applications where adhesives are chosen because of their low cost and easy, fast joining ability (e.g., packaging, consumer products). 

An SVP may be packaged in a vial or an ampule. An LVP may be packaged in a vial, a glass bottle or, in some cases, as a disposable syringe. Packaging material for vials, and ampules are usually composed of type I or II glass. Stoppers and septa in cartridges, and vials are typically composed of elastomeric materials. 

Stoppers and septa in cartridges and syringes are typically composed of elastomeric materials. An overwrap may be used with flexible bags to retard solvent loss and to protect the flexible packaging system from rough handling. 

The U.S. Environmental Protection Agency issued a final rule banning the use of CFC s in flexible plastics and packaging foams, among other uses, after February 15, 1993. Exceptions are CFC-11 and CFC-13 which can be used, temporarily, in mold release agents and the production of plastic and elastomeric materials. However, in 1994, no CFC s will be allowed in flexible foams in the U.S., and a tax will be levied on other CFC uses. Total CFC phaseout is mandated in the U.S. for 1995. 

The polymeric materials usually used to manufacture rigid closures are practically the same as those seen under plastic containers (Section 6.1.3.2). The same impurities are therefore to be expected in these packaging components. On the other hand, though made of polymeric materials, elastomeric closures present a different structure. In the manufacture of rubber, elastomer, the chief component, is combined with other chemicals to produce a material with specific properties that meet target needs, such as its above-mentioned ability to reseal on repeated use. Table 28 lists the common elastomers used in the pharmaceutical industry and their monomeric structures. 

Physicochemical testing is performed to characterize the physical and chemical properties of a plastic to insure that the composition of the synthetic medium will not compromise the quality of the drug being stored within it. To perform these tests, samples of plastic identical to the material being used in the primary package are subjected to an extraction procedure—to dissolve in an extraction solution leachable compounds that are at risk of entering the pharmaceutical preparation. This extraction solution is then subjected to analysis to evaluate the identity and quantity of leachants. For most plastics, the appropriate extraction medium is purified water, but elastomeric closures for use with injections should include extraction with three different extraction... 

Packaging components for parenteral products are generally composed of three items glass/plastic containers, elastomeric closures, and plastic bags. Selection of the packaging components depends on the compatibility between the formulation and the packaging material and on any special requirement of the formulation. 

Butyl rubber is an elastomeric polymer used widely in adhesives and sealants, both as primary binders and as tackifiers and modifiers. Butyl rubber is a copolymer of isobutylene with a small amount of isoprene. These materials have relatively low strength and tend to exhibit creep under load. They are useful in packaging apphcations where their low permeability to gases, vapors, and moisture can be exploited. Butyl rubber is also used as an adhesive sealant. It is generally applied from a solvent-based solution. Table 5.1 summarizes some of the important properties of butyl rubber adhesives. 

Starting material and equipment (provision and quality control of active substances, excipients and packaging material according to specifications, cleaning and disinfection or sterilisation of equipment and primary packaging material e.g. vials, elastomeric closures)... 

Elastomers are electrically insulating materials, usually in the form of silicone rubber pads, ranging in thickness from 0.001 to 0.20 in. and filled with high-thermal-conductivity materials such as alumina and boron nitride. They require a mechanical pressure to fill the voids. Figure 3.13 shows the variation of thermal impedance vs. pressure of an elastomeric pad for a TO-220 package [19]. 

Expert information has been supplied in 47 chapters written by 70 industry specialists, professors, and consultants. Five chapters on fundamentals provide the theoretical and economic underpinnings—why adhesives work, how they are selected, how the surface is prepared, how they are applied, how they are set, how the cured joint is tested. The economic importance of the adhesive-using industries is spelled out, with specifics on the role of adhesives in construction, packaging, autos, aircraft/aerospace, textiles, footwear, abrasives, electronics, and in the home. The next 28 chapters cover the adhesive materials—thermosetting, thermoplastic, elastomeric, natural polymers, cou-... 

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