Preparing dry powder inhalation formulation of salbutamol sulfate using an ultrasonic atomizer device

Inhaled particles must possess certain morphological characteristics to ensure effective drug delivery to the targeted site in the lungs. A modified version of ultrasonic spray pyrolysis was employed to prepare salbutamol sulfate in the form of dry powder. A solution of salbutamol sulfate was atomized using ultrasonic nebulization, and the droplets were transformed into solid drug particles through exposure to high temperature airflow. The engineered salbutamol sulfate samples underwent physical characterization, including particle size, morphology, thermal behavior, and crystallinity analysis. The aerodynamic particle size distribution (APSD) and in vitro deposition of the dry powder inhalation formulation were assessed using the Next Generation Impactor (NGI). The salbutamol sulfate dry powder prepared by the ultrasonic atomizer exhibited an aerodynamic diameter ranging from 1 to 5 μm, as supported by the SEM images. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results showed a significant drop in the crystallinity of the engineered particles. Aerosolization performance studies demonstrated a fine particle fraction (FPF) value (below 5 μm) of 25% for the engineered salbutamol sulfate produced using the ultrasonic atomizer technique, which is acceptable for inhalation purposes. Based on the observed results, this newly introduced method appears to be suitable for producing dry powder formulations of different drugs, with a minimized need for the use of surfactants or stabilizers in the formulation.