Oral Metered Dose Inhaler — Texture Application Note

The use of metered-dose inhalers (MDIs) for the treatment of diseases, such as asthma, has become popular since their introduction in the late 1950s. MDIs come in the form of nasal or oral inhalers and are much appreciated by patients who depend on them for their treatment. MDIs are designed to deliver precise/accurate and reproducible doses of the drug to the lungs or nose. This is crucial as patients rely on their inhaler to deliver the required dose of medication at often crucial times.

Two vital components of the MDI are the metering valve (important in particle size distribution of the delivered dose), and formulation (crucial in defining the physical stability and performance of the MDI). The clinical efficacy of an MDI therefore depends upon the design, reproducibility, formulation and closure system (comprising the valve and its components). This makes MDIs significantly different from other common conventional drug products.