Borosilicate pharmaceutical glasses

Table 2 Typical compositions and thermal expansions of soda lime and borosilicate pharmaceutical glasses...

The neutral glasses are generally less resistant than the hard borosilicate type, but are more easily melted and shaped. They are formulated so that the pH of aqueous solutions is unaffected by contact with the glass, making it particularly suitable in pharmaceutical use for the storage of pH-sensitive drugs. 

In another glass (borosilicate) microreactor [channel dimensions = 350 pm (wide) x 52 pm (deep) x 2.5 cm (long)], Wiles et al. (2004b) prepared a series of 1,2-azoles, illustrating the synthesis of a pharmaceutically relevant core motif. Reactions were performed using electroosmo-tic flow (EOF) as the pumping mechanism and employed separate... 

Compared with the above examples, whereby an array of pharmaceutically important molecules have been synthesized under pressure-driven flow, Garcia-Egido et al. (2002) reported the synthesis of fanetizole (207), an active compound for the treatment of rheumatoid arthritis, utilizing EOF. Employing a borosilicate glass microreactor fabricated at The University of Hull, the authors demonstrated the first example of a heated EOF-controlled reaction. As Scheme 60 illustrates, using... 

Pleated These cartridge filters are typically used in higher-purity applications, such as pharmaceutical and microelectronics. The filters can have a multi-layered construction or be single layer. Typical materials of construction include polypropylene, polyethersulfone, and borosilicate glass fiber. 

There are many different types of glasses made that can have an impact of the photodegradation of pharmaceuticals and their testing results. Among these types are fused quartz, soda-lime, borosilicate (e.g., Pyrex) and a variety of colored glasses. These glasses come in a variety of different shapes such as float, sheet, plate, and cylinder blown glass. They may be chemically treated, coated or laminated with plastic, clear or tinted. 

These products include fiberglass, borosilicate glass, fire retardants, fertilizer, enamels and ceramic glazes, soaps and detergents, cosmetics and pharmaceuticals, and pesticides. Boron also has wood preservation, metallurgical, and nuclear (neutron absorption) applications. 

Boric acid is used in the manufacture of glass (borosilicate glass), glazes and enamels, leather, paper, adhesives, and explosives. It is widely used (particularly in the USA) in detergents, and because of the ability of fused boric acid to dissolve other metal oxides it is used as a flux in brazing and welding. Because of its mild antiseptic properties it is used in the pharmaceutical Industry and as a food preservative. 

For packaging, transportation, storage of Uquids, chemicals, pharmaceuticals, etc., a high variety of hoUowware is produced in the shape of bottles and tubes. Most of the products are made from soda-Ume glass (Table 3.4-3) directly from the glass melt Vials and ampoules are manufactured from tubes for pharmaceuticals these are made from chemically resistant borosilicate glass. 

For pharmaceutical packaging, borosilicate glasses are preferred to standard soda-lime-silica since they are more chemically resistant. In fact, standard glass is not completely inert since mobile alkali are leached into the contained product (Chapter 5). Therefore, low alkaline concentration glass containers have been developed. In the field of elevated temperature applications, low thermal expansion glasses are used. Pyrex glass is the most well known. Some manufacturers also tried to develop tempered containers from standard glass for the same purpose. These resist expansion until thermal shock stresses exceed the built-in residual stresses and then brittle fracture... 

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