Advanced Spray-Dried Cyanidin Chloride Inhalable Dry Powders with High Aerosol Dispersion Performance and Mitochondrial Bioenergetics Modulation for Targeted Pulmonary Delivery

High Resolution Image Download MS PowerPoint Slide Using an organic solution-based, closed-mode spray drying particle engineering approach, Cyanidin chloride, a natural flavonoid with potent antioxidant and anti-inflammatory properties, was designed into inhalable powders for targeted pulmonary delivery using dry powder inhalers. Two different spraying pump rates of 25% and 50% were used for co-spray drying cyanidin chloride with trehalose dihydrate. In addition to in silico computational predictive modeling, particle-engineered powders were comprehensively characterized for physicochemical properties, in vitro partition coefficient, in vitro aerosol dispersion performance and modeling, in vitro human respiratory cell biocompatibility and membrane properties, and in vitro mitochondrial bioenergetics. Scanning electron microscopy and aerodynamic particle size distribution analysis confirmed the formation of inhalable microparticles with an optimal mass median aerodynamic diameter of ∼1.1–1.4 μm. In vitro aerosol performance, assessed using the Next-Generation Impactor with two different FDA-approved dry powder inhaler devices with varying shear stress properties (i.e., the Neohaler and Handihaler devices), demonstrated a high fine particle fraction (>50%), with Neohaler achieving excellent dispersion efficiency (∼88%). The impact of pump rate on aerosolization parameters was minimal, whereas the dry powder inhaler device type significantly influenced geometric standard deviation and fine particle fraction. Cellular dose–response using human respiratory cell lines (A549, H358, Calu-3, and RPMI 2650) indicated excellent biocompatibility up to 100 μM, except in H358 cells, where viability dropped below 80% at this dose. Air–liquid interface human respiratory monolayer studies using Calu-3 cells revealed a transient transepithelial electric resistance reduction at 3 h postexposure, which fully recovered within 24 h, indicating reversible modulation of epithelial permeability. Mitochondrial reactive oxygen species analysis further demonstrated that cyanidin chloride significantly attenuated rotenone-induced mitochondrial reactive oxygen species generation at low micromolar concentrations, with no additional suppression at higher doses. These findings demonstrate for the first time that advanced co-spray-dried powders created by particle engineering design possess favorable aerosolization characteristics, are safe and biocompatible, and well-tolerated at therapeutically relevant doses. Given the high oxidative stress and inflammatory burden in asthma, the inhaled cyanidin chloride dry powder inhaler could provide a localized, lung-targeted therapy to mitigate airway inflammation and oxidative damage. The excellent in vitro aerosolization properties using FDA-approved inhaler devices, favorable safety profile, and mitochondrial bioenergetic effects of inhalable cyanidin chloride co-spray-dried formulation demonstrate its innovative potential for use in asthma and other respiratory conditions.