The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) has developed a harmonised guideline for elemental impurities, Q3D in pharmaceutical products which includes medical gases, referred to as ICH Q3D. This is an adopted guideline from the European Medicines Agency.

ICH Q3D recommends a science and risk-based approach to evaluate the potential for introduction of elemental impurities, into the drug product and to determine if additional controls need to be included in the overall control strategy to ensure product quality and safety.

To determine whether medicinal gases are likely to contain any elemental impurities, specified in ICH Q3D, EIGA members performed a risk assessment which considered which elemental impurities could theoretically be present in the licenced drug products. The maximum daily dosages were also calculated for each medicinal gas to determine which medicinal gases were at the highest risk.

Although the method of production is unique for each medicinal gas, the method of filling and packaging the gases is common across all products. The same basic equipment and procedures are used to fill these products and the container closure systems used are similar for all products. This led to a conclusion that the potential elemental impurities present was common for all medicinal gases.

For those high risk elemental impurities that were identified as potentially being present in the gases, appropriate test procedures were set up to determine their levels in the finished product.

The test method sampling system took product from the container closure system so as to represent the gas that would be delivered to the patient for treatment. This was considered to be the worst-case scenario for all medicinal gases and gas mixtures, to determine whether the elemental impurities would be within the permitted daily exposure limits detailed in ICH Q3D.

From the information given in this report, the view of the EIGA companies is that the levels of elemental impurities within the medicinal gases that they supply for patient treatment are well below the limits set out in ICH Q3D.

This publication is intended for all those you are involved in the supply of medical gases.

The publication is part of the programme to develop Globally Harmonised publications amongst Regional Gas Associations.

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