Microparticulate drug delivery systems for targeting respiratory diseases

Abstract

The respiratory system is highly prone to a number of chronic disorders, which is one of the common health problems all over the world. Administration of therapeutics by oral or parenteral routes leads to minimal bioavailability at the therapeutic site, unwanted adverse events, and required frequent dosing. To overcome the limitations with respect to conventional delivery systems, advanced drug delivery systems like inhalable formulations had attained high priority. Inhalation-based formulations exhibit major challenges with particle size and the elimination of foreign particles from the lungs. The particle size of inhalable formulation has a critical role that can retain within the respiratory part and overcome the disadvantages of alveolar uptake. Micron-size particles like microparticles, microspheres, and microemulsions are found to an attractive strategy for effective delivery of drugs to the targeted sites. These particles can be settled in the deeper part of the respiratory system and overcome the disadvantages of normal powder for inhalation. The micron-size particles are modified as dry powder inhalers with good flow properties. Various techniques have been implemented for microparticle preparation, and modification is implemented to overcome alveolar macrophage uptake and mucoadhesion. The microparticulate systems can overcome the disadvantage of nanoparticles as nanoparticles can be encapsulated in microparticles. This minimizes the engulfing of nanoparticle, aggregation of nanoparticle, and exhalation of nanoparticles. The current microparticle-, microsphere-, and microemulsion-based formulation approaches are discussed to achieve better therapeutic efficacy in the treatment of respiratory disorders.