Abstract

Inhalation therapy is the preferred method for treatment of asthma, chronic obstructive pulmonary disease, and alveolar defects. Oronasal and tracheostomy delivery of devices like a pressurized metered dose inhaler (pMDI), breath actuated pMDI, and soft mist inhaler are preferred for effective aerosol delivery of drugs like bronchodilators, corticosteroids, muco-active agents, etc. Most pMDI devices utilize propellants for generating aerosol while SMI uses a spring as a source of mechanical energy for generating aerosol. Spacers or valved holding chambers and facemasks can be used with pMDIs as accessories to facilitate accurate drug delivery. Optimization of aerosol delivery requires the formulation to be deposited into the lungs and not in the upper respiratory tract, for which the particle size should range from 2 to 5 µm. During selection of the right inhaler device for a patient, factors like the patient’s ability to use the device correctly and adherence are to be considered.