Taking the Evaluation of Orally Inhaled Products in the Laboratory to the Next Level: Introducing the Patient Experience into the Picture




Despite significant advances in the technology associated with the administration of all forms of inhalation therapy, patient adherence in the management of chronic conditions such as asthma and chronic obstructive pulmonary disease (COPD) is poor. The focus of laboratory testing of orally inhaled products (OIPs) has largely ignored the way in which the patient interacts with the device, paying attention instead to requirements for data obtained by methods that are simplified to achieve the necessary degree of robustness. Although such testing is clearly essential in the context of asserting product quality, regulatory agencies are beginning to recognize the need for additional information about performance that relates to the intended user experience. In this context, the drug product and delivery device, including add-ons such as spacers and valved holding chambers (VHCs) used with pressurized metered dose inhalers (pMDIs) have to be treated as a single entity. Laboratory methods simulating age-appropriate breathing patterns, poor coordination of inhaler actuation and inhalation, and the possibility that the patient interface may be a facemask rather than a mouthpiece are therefore needed. It is hoped that such approaches will eventually become incorporated into the suite of compendial methods, once validated satisfactorily. Evaluations of inhalers simulating patient use can be very useful in product design and development phases, where increasing emphasis is being placed on a risk management approach. In this way, the patient adherence problem can be better addressed with the next generation of ‘patient-friendly’ inhalers.