Comparison of ISO standards for device performance; 20072 and 27427: a critical appraisal

Two separate international standards, ISO 20072:2009 and ISO 27427:2010, have recently been published that relate to the development and performance testing of oral inhaled products (OIPs). The scope of ISO 20072 encompasses all OIP forms except nebulizing systems, whereas ISO 27427 was developed specifically for this class of OIP. Compliance with these standards will likely be necessary for manufacturers seeking approval to market inhaler devices in the European Union (EU). Their adoption in the United States may take a considerable time, but the FDA has expressed support in general terms for the ISO process. Key aspects of both standards that are very different in style and content are identified and discussed from the perspective of a potential user. In the approach adopted by ISO 20072, a formalized risk assessment is undertaken as a key part of design verification, in order to develop the Device Functionality Profile (DFP) of the device. The DFP is subsequently verified by the System Verification Test (SVT), in which pharmacopeial test methods are used to evaluate in vitro performance of the device with a chosen drug product in a statistically robust manner. On the other hand, ISO 27427 adopts a more prescriptive approach that involves performance verification of the finished nebulizing system using 1% w/v salbutamol as the test formulation. Although ISO 27427 is currently undergoing revision, at present it is unclear whether the changes that are made will significantly alter its fundamentally different approach to device performance verification. A strong case can be made for a single OIP-wide ISO standard, based on the principles developed in ISO 20072 and that makes use of the well-understood and validated in vitro test procedures that are available or will shortly be available in the case of nebulizing systems, in the United States and European pharmacopeias.