The deadline is rapidly approaching for pharmaceutical manufacturers to implement renewed vigilance for elemental impurities during drug production processes. Under the ICH Q3D guidelines that go into effect on January 1, 2018, manufacturers must test for the presence of 24 elemental impurities in medications.

Although the guidelines do not address glass explicitly, pharmaceutical manufacturers may inadvertently taint their products through the use of inferior sight glass in production vessels. Borosilicate glass is the proper constituent of sight glass windows used in pharmaceutical applications. However, many drug producers are unknowingly using sight glasses made with substandard common soda-lime glass, which has been associated with leaching impurities.

How to determine if a sight glass could leach…

Leached soda-lime glass contaminants are of concern due to their unknown effects on drug quality, yield strength, and shelf life. Both sodium silicate and calcium have been identified in toxicology tests involving soda-lime glass.

In some cases, sight glass suppliers simply ship substandard glass without documentation of its composition. In the worst cases, sight glass suppliers may misrepresent the composition of the glass, shipping soda-lime material that fails to meet the US Pharmacopeia (USP) Type I glass standard.

Sight glasses are currently available that use leach-resistant borosilicate glass. Specifiers should insist on written documentation that the sight glass meets the DIN 7080 standard, ensuring that sufficient boron replaces the soda lime to achieve the highest levels of leach resistance. Such sight glasses meet the USP standard for hydrolytic resistance that is required for Type I glass.

Click here for For information on how to determine if a sight glass could leach, visit http://www.ljstar.com/elemental-impurities-tell-sight-glass-will-leach/.

(Source: L.J. Star Inc.)