Nanomedicine in pulmonary delivery

Abstract

The lung is an attractive target for drug delivery due to noninvasive administration via inhalation aerosols, avoidance of first-pass metabolism, direct delivery to the site of action for the treatment of respiratory diseases, and the availability of a huge surface area for local drug action and systemic absorption of drug. Colloidal carriers (ie, nanocarrier systems) in pulmonary drug delivery offer many advantages such as the potential to achieve relatively uniform distribution of drug dose among the alveoli, achievement of improved solubility of the drug from its own aqueous solubility, a sustained drug release which consequently reduces dosing frequency, improves patient compliance, decreases incidence of side effects, and the potential of drug internalization by cells. This review focuses on the current status and explores the potential of colloidal carriers (ie, nanocarrier systems) in pulmonary drug delivery with special attention to their pharmaceutical aspects. Manufacturing processes, in vitro/in vivo evaluation methods, and regulatory/toxicity issues of nanomedicines in pulmonary delivery are also discussed.

Keywords: colloidal carriers; dendrimer; liposome; nanocarrier systems; polymeric nanoparticle; pulmonary delivery; solid lipid nanoparticle; submicron emulsion.

Figure 1

Examples of drugs for pulmonary colloidal carriers (nanocarrier systems).

Figure 2

Chemical structures of polymers for polymeric nanoparticles in pulmonary delivery systems.

Figure 3

A schematic representation of the spray-drying process.

Figure 4

Molecular structures of sugar carriers: A) α-lactose monohydrate, B) anhydrous β-lactose and C) D-mannitol.

Figure 5

Schematic representations of A) SAS and B) SFEE processes.