ISO 4802-2:2023

Overview

ISO 4802-2:2023 - Glassware - Hydrolytic resistance of the interior surfaces of glass containers - Part 2: Determination by flame spectrometry and classification describes a standardized laboratory method to evaluate how the inner surfaces of glass containers resist hydrolytic attack by water. The test uses controlled heating (121 ± 1 °C for 60 ± 1 min) and quantifies released alkali/alkaline‑earth species (notably sodium) in the extraction solution by flame atomic emission or absorption spectrometry (flame spectrometry). The document also defines a classification system (HC 1, HC 2, HC 3, HC B, HC D) for container hydrolytic resistance.

Key technical topics and requirements

• Test conditions: containers filled with specified water, loosely capped and heated at (121 ± 1) °C for (60 ± 1) min.
• Analytical method: measurement of sodium and other alkali/alkaline‑earth oxides in the extract by flame atomic emission or absorption spectrometry.
• Sample preparation: detailed procedures for cleaning, determination of filling volume (different rules for ampoules, syringes, flat‑ or round‑bottomed containers), and sample size.
• Classification: assignment to hydrolytic classes (HC 1, HC 2, HC 3, HC B, HC D) based on measured ion release and container‑specific limit values. Briefly:
  • HC 1 - neutral/borosilicate glass with very high hydrolytic resistance (suitable for most preparations including parenterals);
  • HC 2 - soda‑lime glass with high resistance due to surface treatment;
  • HC 3 - typical soda‑lime‑silica glass with moderate resistance (often for non‑aqueous or less demanding uses).
• Scope limitations: may not be applicable to containers whose internal surfaces have been functionally modified (e.g., silicone‑coated containers ready for direct filling).
• Harmonization: updated to align cleaning and autoclaving procedures with Ph. Eur.; includes containers down to 0.5 ml filling volume.

Practical applications

• Pharmaceutical packaging qualification: verifying primary packaging (vials, ampoules, syringes, cartridges, bottles) for parenteral and other drug products.
• Quality control and lot release: routine testing to ensure glass batches meet hydrolytic resistance requirements.
• Material selection and supplier qualification: comparing glass types (borosilicate vs soda‑lime‑silica) and surface treatments.
• Regulatory support: producing test reports and classification data required by regulators or pharmacopeial monographs.

Who should use ISO 4802-2:2023

• Quality control laboratories in pharmaceutical and medical device companies
• Packaging engineers and material scientists selecting container types
• Regulatory affairs and compliance teams preparing submissions
• Glass manufacturers and contract testing organizations

Related standards

• ISO 4802-1 (titration method for hydrolytic resistance)
• ISO 719, ISO 720 (hydrolytic resistance of glass grains)
• Ph. Eur. and USP <660> (pharmacopoeial context for glass types and classifications)

Using ISO 4802-2:2023 helps ensure reproducible, comparable hydrolytic resistance data for glass containers and supports safe selection and qualification of primary packaging for pharmaceutical use.