Bioaerogel microparticles (BAMs) possess great porosity and ultralow density, which confers low aerodynamic size and favourable properties for aerosolization. In this study, alginate-based BAMs containing budesonide were constructed using water-in-oil (W/O) emulsion as a template and calcium ion as a gelling agent. The size of water droplets was effectively reduced by powerful mechanical stirring, and the formed BAMs had a mean geometric size of 6.5 µm, as evaluated by image analysis. These BAMs demonstrated excellent aerosolisation performance with 89% w/w emitted from capsule, 45% w/w deposited in the lower stages of the next generation impactor (aerodynamic diameter, Dae < 4.46 µm) and 24.7 % w/w (Dae < 1.66 µm) targeted to the alveolar regions. The MMAD for BAM aerosols was 2.4 µm, further confirming their suitability for penetration to, and deposition in the peripheral regions of lungs. These data strongly suggest that BAMs have great potential to become a mainstay of next generation dry powder systems for effective drug delivery to the lungs.
Li et al. (Wed,) studied this question.