This guideline focuses on the production, control, storage and distribution of medicinal gases. But this document does not cover the manufacture of medicinal gases in hospitals or at home for personal use. However, the principles contained in this document may be applied in those instances to ensure that oxygen generated at hospitals or at home is suitable for intended use and meets the appropriate quality standards.
There is an urgent need to scale up the production of medicinal gases, in particular oxygen, meeting the required quality specifications.
Where the good manufacturing practices (GMP) standards for medicinal gases are not followed, for example in the production and control of industrial oxygen, the purity and content of oxygen could be affected.
The possible contamination of industrial oxygen with viable and non-viable particulate matter, including other impurities, could result in risk to patients when applied for medicinal use.
Industrial oxygen should not be used as a medicinal gas.
Although there are other published guidelines, such as those of the European Union and the Pharmaceutical Inspection Co-operation Scheme (PIC/S), the COVID-19 pandemic resulted in an urgent and increased need for the rational use of oxygen and medicinal gases in many WHO Member States.
Whilst the urgent supply of medicinal gases is necessary, appropriate standards should be followed in all countries for the production, control, storage and distribution of oxygen and other medicinal gases to guarantee that gases for medicinal use are of assured quality when they reach the patients.
The recommendations in this guideline are harmonized with the principles of other similar and published guidelines.
WHO GMP guidelines are reviewed and updated regularly, and are available in the WHO Technical Report Series. Manufacturers and distributors of medicinal gases should comply with the relevant parts of WHO GMP guidelines as well as with the content of this document.
Companies that are involved in the manufacture, control, storage and distribution of medicinal gases should document, implement and maintain a comprehensively designed and clearly defined quality management system. This is the responsibility of senior management.
Records should be maintained for each batch of gas manufactured. These records should include relevant information, as appropriate, such as the following:
- name of the product;
- batch number;
- identification of the person or persons carrying out each significant step;
- equipment used (such as filling manifold);
- quantity of cylinders or mobile cryogenic vessels before filling, including individual identification references and water capacity;
- prefilling operations performed;
- key parameters that are needed to ensure correct fill at standard conditions;
- results of appropriate checks to ensure the containers have been filled;
- specification of the finished product and the results of quality control tests (including reference to the calibration status of the test equipment);
- quantity of rejected cylinders or mobile cryogenic vessels with individual identification references and reasons for rejection;
- details of any problems or unusual events and signed authorization for any deviation from instructions;
- batch label, where applicable;
- specification of the finished product and results of quality control tests (including reference to the calibration status of the test equipment) by the responsible person, with date and signature;
- batch quantity;
- date of testing and certification statement;
- identification reference for the tank (tanker) in which the batch is certified;
- reference to the supplying tanker (tank), reference to the source gas, as applicable.
