Metal–Organic\nFramework Microsphere Formulation\nfor Pulmonary Administration

Abstract

Although nanoscaled metal–organic\nframeworks (nanoMOFs)\nare promising drug carriers, their appropriate formulation remains\nalmost unexplored and basically restricted to intravenous routes.\nLungs, beneficiating from a large absorption surface and low enzymatic\npresence, are a very attractive target for both local and systemic\ndelivery. However, pulmonary nanoMOF formulation is a pending and\ndefying task. Thus, we propose a pioneer nanoMOF-based microsphere\nsystem as a potential platform for pulmonary administration. A biocompatible\nnanoMOF was successfully encapsulated in mannitol by a simple and\ncontinuous spray-drying technique. Upon intratracheal administration\nto rats, the resulting formulation, exhibiting optimal properties\n(<i>i.e</i>., homogeneity, size, density, and spray-drying\nprocess yield), was able to release the intact nanoMOF carrier uniformly\nalong the lungs, reaching the bronchioles and alveoli.