Rodos m disperser

The primary particle volumetric diameter (Dv) of each formulation was determined by laser diffraction using the Sympatec HELOS (submicron R1 lens with 20 mm focal length) equipped with RODOS/M disperser and ASPIROS sample feeder (Sympatec GmbH, Germany). Powder formulations were dispersed at a pressure of 4 bar. The span was calculated and reported for each measurement using the following equation
$$\mathit{\text{Span}}=(Dv90-Dv10)/Dv50.$$

A Sympatec HELOS laser diffraction apparatus equipped with RODOS/M disperser and ASPIROS sample feeder (Sympatec GmbH, Clausthal-Zellerfeld, Germany) was used to determine the primary particle size distributions of the spray-dried Survanta-EEG powders. Powder samples placed into the ASPIROS sample feeder were dispersed in the laser beam at 1.0 and 4.5 bar dispersion pressure using the RODOS/M disperser. Low dispersion pressure (1.0 bar) was used to get the idea about powder dispersion behavior and higher dispersion pressure (4.5 bar) was used to get the primary particle size of the powder particles. Particle size distributions (Dv10, Dv50 and Dv90) of the powders were calculated using Fraunhofer theory in the WINDOX 5.0 software (Sympatec GmbH, Clausthal-Zellerfeld, Germany). The Sympatec software was used to calculate particle fractions less than 1 and 5 µm, respectively. A total of ten batches of spray-dried powders were used in this study.