ABSTRACT
Asthma and chronic obstructive pulmonary diseases (COPDs) such as bronchitis and emphysema are major and growing disease areas where the major route of administration is topically, at the site of action in the lung. Asthma is a common, chronic disease with a prevalence of more than 5 percent in adults and 15-20 percent in children, and is increasing in many parts of the world. The prevalence of COPD is even higher, and mortality rates are 10 times higher than those for asthma. At present, similar drugs are used for both diseases, with steroids and short-and long-acting 2s being the most common therapies. Anticholinergics and chromones are also employed. Inhalation allows the delivery of smaller doses directly to the lungs, with the advantage of reduced systemic side-effects. There are also other illnesses where pulmonary delivery is appropriate, such as cystic fibrosis, human immunodeficiency virus (HIV), lung cancer, pain and infections. In addition, the lung is being increasingly viewed as a route to the systemic circulation for the treatment of non-respiratory diseases, where normal oral administration is not technically possible. This is especially relevant to the delivery of peptides and proteins, of which insulin is a good example.
