Plastics pharmaceutical applications

The interest in mineral-promoted organic reactions stems from the need to understand the fate of pesticides in soils and pollutants in sedimentary environments (8), petrogenesis (20-27), humification (19, 28, 29), the origin and evolution of life (1, 30), the use of clays as catalysts in industrial processes (31-37), in pharmaceutical applications (3), and as pigments and fillers in paper, plastic, and rubber (37). 

In pharmaceutical applications, sorbitol is used as a tablet diluent in wet granulation or dry compression formulations. It is commonly used in chewable tablets because of its sweet taste, and it is also used as a plasticizer for gelatin in capsule formulations. Sorbitol is utilized in sugar-free liquid preparations and as a stabilizer for drug, vitamin, and antacid suspensions. When it is used in syrups, crystallization around bottle caps is prevented. 

Industrial calcium carbonate (CaCOs) is mainly produced by extraction/milling of natural ore. Suitable ore-bodies include chalk, limestone, marble, and travertine. Sufficiently pure ore-bodies are selected to allow direct exploitation. The main applications include paper, paints, plastics, pharmaceuticals, etc. Luminescence and LIBS (Fig. 8.3) sorting may be used for calcium carbonate ore radiometric sorting. 

Sometimes particles are encouraged to agglomerate to yield granules, for example, for pharmaceutical applications which may require the addition of liquids or other binders. In the ceramics, paint, plastics and rubber industries, however, reducing or eliminating agglomerate formation is of overriding importance. 

V. Stoy, and C. Kliment, Hydrogels Speciality plastics for biomedical and pharmaceutical applications, (Technomic Pub., Basel, 1996). 

The modern use of glass has been somewhat reduced by the advent of plastics. Despite the durability and cost-effectiveness of plastic containers, plastic has not permeated all pharmaceutical applications. Glass is still the most attractive packaging material where chemical inertness, very low moisture and gas permeability, and heat resistance are concerned. Modern uses of glass are typically restricted to injectable liquids for parenteral use ° and other sterile preparations. ... 

Dimethyl phthalate is used in pharmaceutical applications as a solvent and plasticizer for film-coatings such as hydroxypropyl methylcellulose, cellulose acetate and cellulose acetate-butyrate mixtures. ... 

The earliest reported pharmaceutical applications of roller compaction were published in 1966 (12). A typical formulation for roller compaction wilt contain a fragmenting material (e.g., lactose), a plastically deforming material such as MCC or com starch, binder (e.g., hydroxyIpropylmethylce Iulose. HPMC). actives, and lubricants (magnesium stearate). 

HPLC is widely used in the chemical and plastics industries. Applications in the chemical industry are quite similar to those for testing pharmaceutical ingredients. They include assay and purity testing of synthetic chemicals such as raw materials, precursors, monomers, surfactants, detergents, and dyes.27,28 In the plastics industry, GPC is used for polymer characterization in product research and quality control. RPC is used in the determination of polymer additives. 

A few plastics which tend to be naturally brittle require an improvement in both their drop (impact) strength and their top loading (compression) strength. In the case of polystyrene, rubber is widely used as an impact modifier. Rigid PVC, particularly when used as a container, may suffer weakness when subjected to, say, a 3 4 foot drop test. Up to 15% of methyl methacrylate butadiene styrene (MBS) copolymer is usually added to improve impact strength. Chlorinated polyethylene has more recently been introduced as a PVC impact modifier. Vinyl acetate is frequently used as a modifier for PVC film. Polythene, LDPE-HOPE can have resistance to stress (environmental stress cracking), improved by the use either of rubber or polyisobutylene. These modifications have not as yet had any pharmaceutical applications. 

Although rotational moulding is used for both plastics and rubber, pharmaceutical applications, other than for rubber mouldings, are unlikely. 

Clean manufacturing facilities plus adequate GMP back-up are now essential for producing many plastic containers and components for pharmaceutical applications. 

Any new super-plastic, unless it matches the economics of the above, will take at least 10-20 years before it becomes a commercially successful material with wide pharmaceutical applications. 

The emotive issues related to plastic and the environment have yet to be logically and scientifically resolved. However, predictable future trends which will increase the use of plastics in pharmaceutical applications are likely to include ... 

It therefore can be concluded that there is considerable confusion in Europe associated with the use of plastics for pharmaceutical applications generally. The following food legislation has been introduced ... 

The properties of metal and plastic have been combined in the form of a laminated tube, which consists of a polyethylene/ aluminium foil/polyethylene or similar laminated body fitted with a polyethylene nozzle and is less permeable than a conventional polyethylene tube with less tendency to draw air back. To date the main usage of laminated tubes has been for toothpastes, but wider pharmaceutical applications are now found. 

There are many different types of plastics and an even greater number of grades to meet virtually every product requirement. The main economical plastics used in pharmaceutical applications are the economical four i.e. polyethylene, polypropylene, polystyrene and polyvinylchloride. 

Plastics are used in virtually every pharmaceutical application (oral, topical, ophlthalmic, parenteral applications), either as a single material or in combination with other materials, as coatings or laminations. 

Industry has applied radiotracers in a very large variety of ways. More than half of the SOO largest manufacturing concerns in the United States use radioisotopes in the production of metals, chemicals, plastics, pharmaceuticals, paper, rubber, clay and glass products, food, tobacco, textiles, and many other products. Radioisotopes are used to study mixing efficiency, effect of chamber geometry, residence time in reactors, flow rates and patterns in columns and towers for fractionation, absorption, racemization, etc. Some of die many uses are listed in Table 9.6 and a few are described below to reflect the scope and value of the industrial applications of radioisotopes. Quite often the radionuclide used is not isotopic with the system studied. 

In processes illustrated on these figures, plasticizers are required for final product performance to increase elastic properties of manufactured products. Gloves are coated with rubber latex. Its viscosity is adjusted by the plasticizer. Caplet coating for pharmaceutical applications is done by immersion in a gelatin solution where water is solvent and processing plasticizer. 

Sulfoxides and sulfones (Figure 9.13) contain both sulfur and oxygen. Dimethylsulfoxide (DMSO) is a liquid used to remove paint and varnish, as a hydraulic fluid, mixed with water as an antifreeze solution, and in pharmaceutical applications as an anti-inflammatory and bacteriostatic agent. Sulfolane dissolves both organic and inorganic solutes and is widely used in BTX processing to selectively extract benzene, toluene, and xylene from aliphatic hycbocarbons as the solvent in the Sulfinol process by which thiols and acidic compounds are removed from natural gas as a solvent for polymerization reactions and as a polymer plasticizer. 

Plastics. In 1847 it was discovered that cellulose nitrate could be dissolved in a mixtin-e of ether and alcohol to produce a solution called collodion. Collodion is still in use today in pharmaceutical applications. Combination of nitrocellulose with castor oil and eventually camphor by Parkes (1862) and Hyatt (1870) led to the production of celluloid and ultimately the birth of the plastics industry. 

Ghebremeskel A, Vemavarapu C et al (2007) Use of surfactants as plasticizers in preparing solid dispersions of poorly soluble API selection of polymer-surfactant combinations using solubility parameters and testing the processability. Int J Pharm 328(2) 119-129 Gogos C, Liu H (2012) Laminar dispersive and distributive mixing with dissolution and applications to hot-melt extrusion. In Douroumis D (ed) Hot-melt extrusion pharmaceutical applications. Wiley, New York, pp 261-284... 

Booy ML (1963) Influence of Channel Curvature on Flow, Pressure Distribution and Power Requirements of Screw Pumps and Melt Extmders, Soc Plastics Engrs Trans., 3 pp 176. Cameiro OS, Covas JA et al (2000) Experimental and theoretical study of twin-screw extrasion of polypropylene. J Appl Polym Sci 78(7) 1419-1430 Che D, KotipaUi U et al (2010) Atorvastatin calcium propylene glycol solvates, USPTO Crowley MM, Zhang F et al (2007) Pharmaceutical applications of hot-melt extrusion part I. Drug Dev Ind Pharm 33(9) 909-926... 

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