USP is Announcing a Proposal to Modify the Glass General Chapter <660>

The USP is proposing to revise General Chapter <660> Container—Glass, consistent with a recent FDA request to revise the Type 1 definition of glass in <660> from one that is composition based to one that is performance based. The request highlighted the FDA’s concern about global issues regarding glass production and resulting drug shortages.  The agency is supportive of the use of new glass compositions for parenteral products if they demonstrate suitability for the product.


Over the past several years, there have been reported shortages of glass vials. Products such as the COVID-19 vaccines and other parenteral products are packaged for delivery and administration in glass vials. Shortages of these vials could threaten the availability of these and other important products. In response to supply chain issues for glass vials, drug product manufacturers could propose to FDA the use of new packaging compositions (e.g. aluminosilicate) that are suitable for their intended use with specified drug products. However, a number of official monographs in the USP-NF require the use of a specific glass type, for example “Type I glass” or “Type II glass.” The current General Chapter <660> defines glass types by composition-based characteristics, e.g., “Type I glass” is defined as (neutral) borosilicate glass. Thus, manufacturers submitting a drug application to FDA for a drug product for which a USP-NF monograph with specific packaging requirements exists, could face regulatory hurdles if the product uses a new or different packaging composition from what is specified in the relevant monograph. Moreover, the corresponding Ph. Eur. Chapter 3.2.1 Glass containers for pharmaceutical use currently also defines type I glass as neutral (borosilicate) glass.

To address these challenges, the proposed compendial revisions would include the following:

  • Revisions to General Chapter <660> to remove glass classifications based on composition. Currently, <660> defines: Type I (borosilicate (neutral) glass); Type II (treated soda-lime silica); and Type III (soda-lime silica). Under the proposal, General Chapter <660> would instead define glass Types I, II, and III by performance characteristics, allowing for additional compositions (e.g. aluminosilicate) to be considered Type I, II, and III glass. However, there are no proposed changes to test procedures or acceptance criteria.  

  • Revisions to 14 monographs that currently prescribe a specific glass type by adding the word “preferably” in the packaging section of the monograph. The addition of the word “preferably” to the monographs means that the use of the glass specified is preferred, but not required. According to the announcement, the proposed revision "will give manufacturers additional flexibility in their choice of packaging and pave the way for new or different types of packaging to be approved".

It is expected that the revision to General Chapter <660> will be published in Pharmacopeial Forum PF 49(2) [March-April 2023], with a comment deadline of 31 May 2023. Please see the Notice of Intent to Revise: <660> Container-Glass for additional details.

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