Centrifugal air-assisted melt agglomeration for fast-release "granulet" design : development of a bladeless prototype / Nafisah Musa

Conventional melt pelletization and granulation processes produce round and dense,
and irregularly shaped but porous agglomerates respectively. This study aimed to
design centrifugal air-assisted melt agglomeration technology for manufacture of
spherical and yet porous "granulets" for ease of downstream manufacturing and
enhancing drug release. A bladeless agglomerator, which utilized shear-free air stream
to mass the powder mixture of lactose filler, polyethylene glycol binder and poorly
water-soluble tolbutamide drug into "granulets", was developed. The inclination angle
and number of vane, air-impermeable surface area of air guide, processing
temperature, binder content and molecular weight were investigated with reference to
"granulet" size, shape, texture and drug release properties. Unlike fluid-bed melt
agglomeration with vertical processing air flow, the air stream in the present
technology moved centrifugally to roll the processing mass into spherical but porous
"granulets" with a drug release propensity higher than physical powder mixture,
unprocessed drug and dense pellets prepared using high shear mixer. The fast-release
attribute of "granulets" was ascribed to porous matrix formed with a high level of
polyethylene glycol as solubilizer. The agglomeration and drug release outcomes of
centrifugal air-assisted technology are unmet by the existing high shear and fluid-bed
melt agglomeration techniques.