Inhaled therapy is determined by the needs of individual therapeutic interventions. Inhalation therapy has been used for thousands of years in many forms and applications. Inhaler design has remained mostly unchanged over the last decade; however some aspects have resulted in advancements that provide new disease treatment options. The structure and design of an inhaler have a significant impact on the quantity of aerosol that is deposited in the lungs. An ideal inhaler should deliver precise and regular doses to a specific area of the lungs whilst maintaining drug stability. It's also ideal if the devices are compact and simple enough for patients to operate.