Solvent-free technological processes: melt-extrusion and spray congealing

This area of research consists in the production of oral solid dosage forms by means of a single technological step and in the absence of solvents.  The main ingredients are pharmaceutical grade excipients with low melting point which are melted or softened during the process, and act as binder and / or carrier for the active ingredient. With appropriate choice of the material, the drug release can be appropriately  tailored (performing an accelerated or retarded release).

In the case of the spray-congealing,  microspheres or microcapsules, characterized by highly spherical shape and highly uniform size can be produced by spraying with ultrasounds the carrier.  The drug can be included in a dissolved or dispersed state depending on the affinity with the excipient.

In the case of melt extrusion (and melt co-extrusion), it is possible to realize extrudates from the desired shape (solid and hollow cylinders, helices, sheet,  etc.) through the use of dies of different shape. The selection of the process (temperature, pressure, etc.) and formulation variables (amount of softened binder, auxiliary fillers and active) permits together with the different  mass-to-surface ratio of the different shapes to obtain the desired in vitro and in vivo drug release (as presented in the figure).


Mario Grassi (Dept. Engineering and Architecture), Barbara Campisi (DEAMS), Nadia Passerini (Univ. of Bologna), Beatrice Albertini (Univ. of Bologna), Stefano Dall’Acqua (Univ. of Padova) Peter Kleinebudde (H. Heine University), João F. Pinto (Univ. Lisbon), Iztok Grabnar (Univ. Ljubljiana), Roger Phan-Tan-Lou (Univ. Aix-en- Provence).


Last update: 08-23-2019 - 19:50