Approaches and Devices Used in Pulmonary Drug Delivery System: A Review

Targeting drug delivery into the lungs has become one of the most important aspects of systemic or local drug delivery. Consequently, in the last few years, techniques and new drug delivery devices intended to deliver drugs into the lungs have been widely developed. Currently, the main drug targeting regimens include direct application of a drug into the lungs, mostly by inhalation therapy using either pressurized metered dose inhalers (pMDI) or dry powder inhalers (DPI). Intratracheal administration is commonly used as a first approach in lung drug delivery in vivo. To convey a sufficient dose of drug to the lungs, suitable drug carriers are required. These can be solid, liquid, or gaseous excipients. Liposomes, nano and microparticles, cyclodextrins, microemulsions, micelles, suspensions, or solutions are all examples of this type of pharmaceutical carrier that have been successfully used to target drugs into lungs. The use of micro reservoir type systems offers clear advantages, such as high loading capacity and possibility of controlling size and permeability, and thus of controlling the release kinetics of the drugs from the carrier systems. These systems make it possible to use relatively small numbers of vector molecules to deliver substantial amounts of a drug to the target. This review discusses the approaches and devices required to be administer drug into the lungs.