Exogenous surfactant as a drug delivery agent

Pulmonary surfactant is a complex mixture of lipids and several specific surfactant proteins, which together render it with unique spreading properties and a dynamic surface tension behavior. These characteristics are heralded as ideal for a carrier of choice to instil therapeutic agents into the lung, because this combination enables high local therapeutic levels while minimizing systemic side-effects of the instilled agent. This review outlines the rationale to use exogenous surfactant in lung injury, including opening-up inaccessible regions of the lung to other therapeutic agents. Especially the combination of anti-microbial agents and surfactant offers an alternative for critically ill patients with pneumonia. Some caution is also indicated in combining surfactant with antibiotics without proper evaluation of possible interactions. Some other applications for surfactant as a carrier are discussed. Overall, the benefits of surfactant as a carrier warrants clinical trials and promises additional therapeutic tools for the clinician.