Carbohydrate-based Trojan microparticles as carriers for pulmonary delivery of lipid nanocapsules using dry powder inhalation

Abstract

This study proposes lipid nanocapsules (LNCs)-based Trojan particles made by entrapping 59 ± 3 nm LNCs in carbohydrate-based microparticles via spray drying. This work focused on optimisation of maintenance of the nanocarrier colloidal properties, solid state properties and suitability of Trojan particles for pulmonary deposition. The properties of Trojan particles were evaluated as a function of the nature of carbohydrate, the feed concentration and LNC loading. The presence of nanocapsules had a significant impact on the size and morphology of microparticles and their solid state properties. Spray drying did not destroy the LNCs and their size after reconstitution varied between 78 ± 1 and 121 ± 1 nm. The lactose, trehalose and raffinose-based Trojan particles were readily dispersed as aerosols with mass median aerodynamic diameters between 5.3 ± 0.1 and 6.2 ± 0.1 μm using a dry powder inhaler. In conclusion, LNC-Trojan particles were shown to successfully not only to encapsulate the lipid nanocapsules but also to release them.