Importance of wet packability of component particles in pellet formation

Srimanta Sarkar, Tin Wui Wong, Celine Valeria Liew

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)


This work explored the importance of packability of component particles in the different wet processing steps of extrusion-spheronization and investigated different processing and formulation approaches for enhancing packing of component particles during extrusion-spheronization to produce spherical pellets with high yield and narrow size distribution. Various cross-linked polyvinyl pyrrolidone (XPVP) and lactose grades with different particle sizes were used as pelletization aid and filler in 1:3 binary powder blends. Loosely packed extrudates obtained from coarse XPVP/lactose blends possessed low cohesive strength and produced irregular shaped pellets with low yield whereas tightly packed, rigid extrudates obtained from XPVP/fine lactose grades possessed high cohesive strength and produced elongated pellets. Adjustment of spheronization tip speed to provide sufficient forces generated by the rotating frictional base plate for facilitating packing by rearrangement of component particles improved pellet quality. Double extrusion, decreasing particle size of the formulation component(s), and/or widening particle size distribution of the powder blend are approaches applicable to improve cohesiveness of moistened mass by closer packing of component particles for production of good quality pellets.

Original languageEnglish
Pages (from-to)1267-1277
Number of pages11
JournalAAPS PharmSciTech
Issue number3
Publication statusPublished - Sept 2013
Externally publishedYes


  • cross-linked polyvinyl pyrrolidone
  • extrusion
  • packing
  • spheronization

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