Preparation of peptide and protein powders for inhalation.

Innovations in biotechnology and recombinant techniques have led to a large increase in the number of macromolecule drugs developed over the last several years. These molecules are enabling new therapies for many previously untreated or poorly treated diseases. Due to poor oral absorption, most biopharmaceuticals are delivered by injection. Medical science, health care providers and consumers have been searching for alternative methods of delivering macromolecule drugs. Animal and human clinical studies have demonstrated that pharmacological doses of bioactive peptides and proteins pass, by a natural biological process, from the lungs into the bloodstream or local tissue. New macromolecule drugs are also being developed for treatment of respiratory diseases such as cystic fibrosis, adult and infant respiratory distress syndromes, asthma and emphysema. This paper reviews formulations for delivering therapeutic aerosols to the lungs. Particular emphasis will be placed on preparing fine powders containing macromolecule drugs.