Ensuring Pharmaceutical Glass Packaging Safety: A Guide to USP <660>

What is USP <660>?

In the pharmaceutical industry, protection, compliance, and safety of drug products are critical drivers for primary packaging selection. As drug formulations become more sensitive and regulatory oversight intensifies, meeting industry standards and evaluating packaging materials using standardized performance and testing helps ensure that glass container closure systems do not compromise the drug product's stability, efficacy, or shelf life.

To address these concerns, the U.S. Pharmacopeia (USP) developed USP <660>, a standard that defines the testing requirements for glass containers for pharmaceutical use intended to come into direct contact with injectable pharmaceutical preparations. Originally, USP <660> focused on hydrolytic resistance (the ability to withstand chemical attack by the drug and aqueous content) based on glass composition, with tests and procedures dating back to the 1960s. In 2023, revisions to the USP General Chapter <660> Containers - Glass were published migrating from a “composition based” to a “performance based” glass definition.

While the USP <660> revisions maintained its foundational focus on drug safety and integrity it was expanded to include glass performance, improve standardization across glass material types, account for glass material innovation, and newer analytical methods. Further, replacing the Glass Grains Test with an Elemental Composition by wavelength dispersive X-ray fluorescence (WDXRF) and extractable arsenic test using ICP technology and providing updated guidance on autoclaving and inner surface hydrolytic resistance test. For colored glass, the chapter refines the spectral transmission test. Additionally, changes are pending to the general information chapter of the USP <1660> defining “Evaluation of the Inner Surface Durability of Glass Containers.”

What Is USP <660> Testing?

USP <660> testing refers to the series of analytical evaluations of glass tubing and converted glass containers required to confirm that packaging materials meet the criteria laid out in USP <660>. These tests are critical for verifying the glass packaging performs as intended when in contact with drug product.

In USP <660>, converted glass materials are qualified to ensure suitability for pharmaceutical packaging using the Surface Glass Test and quantifiable WDXRF which replaced the qualitative Glass Grains Test. These tests assess the hydrolytic resistance of the converted glass surface and quantify the elemental composition of the bulk material - ultimately assuring its ability to resist chemical attack from aqueous liquids and drug content.

These revisions align with USP <1660> "Evaluation of the Inner Surface Durability of Glass Containers," providing predictive screening and potential for the formation of glass particles and delamination (6).

Why It Matters

Packaging that fails USP <660> testing can jeopardize not only the quality of a pharmaceutical product but also patient safety. The central concerns are extractables and leachables (E&L), which are potential contaminants that can migrate from the surface of the glass container into the drug product. This can occur when the glass surface is in contact with strong solvents and high pH content, under harsh storage conditions, and if the glass surface has a propensity to delaminate.

Following a previously issued draft, the final version of the revised USP <660> chapters were published and made official on October 1, 2023 (7).

Choose Packaging That Meets the New USP <660> Standards

DWK’s tubular glass vials meet the stringent quality and regulatory expectations required for pharmaceutical packaging, offering a reliable solution even as the industry adapts to evolving standards produced under ISO 15378 and aligned with global compendial requirements for injectable packaging, our vials are engineered for chemical resistance and delamination control. Backed by decades of material science, manufacturing expertise, and strict quality control, DWK ensures packaging performance that supports USP <660> compliance, drug integrity, and patient safety.

This path to compliance starts with choosing the right partners and packaging solutions. DWK is here to help.

Explore our tubular vial solutions or get in touch for help with your packaging compliance strategy.

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