Pelletization techniques used in pharmaceutical fields

Pelle za on is a technique that enables the forma on of spherical beads or pellets with a mean diameter usually ranging from 0.5 to 2.0 mm. These pellets can evantually be coated and very o en used in controlled-release dosage forms. The use of pelle za on and pellets leads to an improvement in the fl owability, appearance and mixing proper es, thus avoiding excessive dust and reducing segrega on and, generally, elimina ng undesirable proper es and improving the physical or chemical proper es of fi ne powders. Pellets are prepared by diff erent techniques, such as extrusion and spheronisa on, rotogranula on, solu on, suspension or powder layering, spray-drying or spray-congealing. The aim of this paper is to review some general aspects about pellets and pelle za on and some common techniques used in the pharmaceu cal industry. Several alterna ve methods are currently being developed, such as: hot-melt extrusion, freeze pelle za on, emulsion / solvent evapora on, granula on using foamed aqueous binders, etc. (1-7).