title: Tablet formulation of an active pharmaceutical ingredient with a sticking and filming problem: direct compression and dry granulation evaluations.
abstract: OBJECTIVE
  To develop a tablet formulation for an active pharmaceutical ingredient for which sticking and filming problems occurred during tablet punching.
  
  
  METHODS
  Direct compression and dry granulation tableting techniques were evaluated using factorial experimental design. The effects of chrome-coated punch tips, filler types and active percent in the tablet formulation by direct compression were evaluated. Similarly, for dry granulation using the roller compaction technique, three formulation factors - roller compaction pressure, intragranular filler percent and filler type - were studied. Tablets prepared by both techniques were characterized in regard to their compressibility index, tablet hardness, disintegration time, friability index and stickiness-filming index (an arbitrary index). Ten formulations were prepared by each technique. Using multiple response optimizations and estimated response surface plots, the data were analyzed to identify optimum levels for the formulation factors.
  
  
  RESULTS
  Compressibility index values for all the formulations prepared by direct compression exceeded 25%, unlike the blends prepared by dry granulation. Both tablet hardness and disintegration time for direct compression formulations were significantly lower than for dry granulation formulations. The friability index values were significantly higher for direct compression formulations than for dry granulation formulations. All the direct compression formulations, unlike the dry granulation formulations, had a high stickiness-filming index.
  
  
  CONCLUSIONS
  Statistical analysis helped in identifying the optimum levels of formulation factors, as well as the method for eliminating sticking and filming. Unlike the direct compression technique, dry granulation yielded tablets for which sticking and filming were completely eliminated.
authors.affiliation: SRI International , Menlo Park, CA , USA.
authors.forename: Naveen K
authors.initials: NK
authors.lastname: Bejugam
authors.forename: Shravan K
authors.initials: SK
authors.lastname: Mutyam
authors.forename: Gita N
authors.initials: GN
authors.lastname: Shankar
mesh_terms: D002482:Cellulose / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000295:instrumentation / Q000379:methods*; D019245:Compressive Strength; D005079:Excipients / Q000737:chemistry; D006244:Hardness; D006801:Humans; D013607:Tablets / Q000737:chemistry*
chemical_list: D005079:Excipients; D013607:Tablets; D002482:Cellulose; C109691:microcrystalline cellulose
keywords: Direct compression; dry granulation; roller compaction; statistical design; stickiness; tablets