Pelletization by Extrusion Spheronization Technique: An Excipient Review

Pellets/spheres have gained wide popularity amongst solid dosage forms due to numerous advantages offered by their spheroid nature and each pellet acting as a seperate drug delivery device. At an industrial scale, pellets are manufactured by extrusion-spheronization technique (ES) however, alternative techniques are also available. Such pellets obtained may be used as neutral or drug loaded pellets. Till date, microcrystalline cellulose (MCC) was considered as a golden standard for ES. Prior to MCC, sugar pareils were used as inert cores for drug loading. But due to physicochemical interactions of MCC, and technological difficulties faced during processing of MCC and sugar pellets, the need for the search of newer excipients as a pelletization aid has been triggered. To name a few, chitosan, carrageenan, starch, pectin, talc etc are being explored. The present review is an attempt to take account of the excipients used to design multiple unit particulate systems (MUPS) by ES technique and propose prospective excipient combinations to overcome limitations of existing pellets and excipients thereof.