Impact of process variables on the micromeritic and physicochemical properties of spray-dried porous microparticles, part I: introduction of a new morphology classification system

Abstract

Alteration of spray drying process variables, particularly solvent composition and feed concentration can have a significant effect on the morphology of spray dried microparticulate products. Morphology of spray dried particles may be usefully described using the morphology classification system.

Formulation, stability and pharmacokinetics of sugar-based salmon calcitonin-loaded nanoporous/nanoparticulate microparticles (NPMPs) for inhalation

“…The composite systems sCT:T: HPbCD 5:57:38 and 5:38:57 also presented porous irregularshaped particles, type 2BIIIa ( Fig. 1f and g) (Paluch et al, 2012).…”

“…SE micrographs showed spray dried powders to be, in general, constituted of spherical porous particles, type 1BIIIa as classified by Paluch et al (2012) (Fig. 1).…”

“…More recently a novel morphology classification system for porous microparticles was introduced by Paluch et al (2012) and is applied in the present study.…”

Spray-Drying of Biopharmaceuticals

“…Freeze-drying results in very little loss during drying, whereas yield is a persistent drawback with spray-drying, particularly with small particles, which may not efficiently deposit in the cyclone [37]. The choice of the optimal drying method is largely determined by the tolerable operating temperature for a specific biopharmaceutical and the final dosage form.…”

“…The main factors that influence the stability and activity of biopharmaceuticals during spray-drying are inlet temperature, oxygen environment, and inclusion of stabilizing excipients. Vaccines and proteins can be successfully spray-dried with little physical or chemical damage [37,41,42] and will be discussed further in section "Challenges Specific to Spray-Dried Biopharmaceuticals." Excipients such as amino acids, sugars, and polymers may be incorporated in the formulation to stabilize biopharmaceuticals during the spray-drying process and for long-term storage following spray-drying [43,44].…”