[Design and Biopharmaceutical Evaluations of Peptide-loaded Inhalable Formulation to Control Pharmacokinetic Behavior].

Recently, biologics including peptides, proteins, antibodies, and nucleic acids have attracted interest as drug candidates for new modalities, since these compounds can act on target molecules that are not be affected by conventional drugs with a small molecular weight to promote greater selectivity, potency, and safety. Generally, to administer biologics, parenteral routes like intravenous and intramuscular injections have been mainly selected due to their poor oral absorbability and stability in the gastrointestinal tract, which can adversely affect patient compliance. Depending on the target diseases, inhalable formulations can be used to achieve both topical effects in the respiratory tracts and systemic actions due to the characteristics of the pulmonary site, including a large surface area, abundant capillary network, thin membrane with adequate permeability for macromolecules, reduced enzymatic degradation, and a lack of first-pass metabolism. In this study, to achieve desirable delivery of peptide drugs with an inhalable formulation to target sites in the respiratory tract and/or absorption sites in the lung, peptide-loaded inhalable formulations were designed by the application of flash nanoprecipitation, one of the precipitation methods to prepare functional nanoparticles, and the fine droplet drying process, a powderization technique using printing technology, to control the pharmacokinetic behavior. From the findings of the study, the strategic applications of these techniques could contribute to provide peptide-loaded inhalable formulations to enhance their biopharmaceutical potentials.