Crystallization induced flower-like lactose as potential carriers for dry powder inhaler application

The study documents the flower-like lactose particles as potential carriers to improve Dry Powder Inhaler (DPI) efficiency. The lactose particles (LMx, LMf) are prepared by anti-solvent crystallization and compared with commercial lactose carriers (Inhalac 251; LMc). Formulations of 1.48% w/w drug loading are prepared using salbutamol sulfate (model drug) and different lactose carriers. The carrier properties are correlated with %FPF using principal component analysis. The analytical results confirm LMx is α-lactose monohydrate, LMf comprises α and β-lactose. Time-resolved crystal growth shows that the LMx particle is agglomerated structure while, LMf particle appear as flower-like structure of size (~45.37–63.92 μm) with high surface and aerodynamic properties compared to LMc. The in-vitro aerosolization studies resulted in higher fine particle fraction (%FPF) for formulations with LMx (~33.23%) and LMf (~44.85%) compared to LMc (~23.40%). The high %FPF is mainly attributed to the higher surface roughness, amorphicity, surface energy of engineered lactose carriers.