title: Method to study the effect of blend flowability on the homogeneity of acetaminophen.
abstract: BACKGROUND
  Excipient selection is key to product development because it affects their processability and physical properties, which ultimately affect the quality attributes of the pharmaceutical product.
  
  
  OBJECTIVE
  To study how the flowability of lubricated formulations affects acetaminophen (APAP) homogeneity.
  
  
  METHODS
  The formulations studied here contain one of two types of cellulose (Avicel 102 or Ceollus KG-802), one of three grades of Mallinckrodt APAP (fine, semi-fine, or micronized), lactose (Fast-Flo) and magnesium stearate. These components are mixed in a 300-liter bin blender. Blend flowability is assessed with the Gravitational Displacement Rheometer. APAP homogeneity is assessed with off-line NIR.
  
  
  RESULTS
  Excluding blends dominated by segregation, there is a trend between APAP homogeneity and blend flow index. Blend flowability is affected by the type of microcrystalline cellulose and by the APAP grade.
  
  
  CONCLUSIONS
  The preliminary results suggest that the methodology used in this paper is adequate to study of the effect of blend flow index on APAP homogeneity.
authors.affiliation: Research Center Pharmaceutical Engineering GmbH, Graz, Austria. marcosllusa@yahoo.com
authors.forename: Marcos
authors.initials: M
authors.lastname: Llusá
authors.forename: Kalyana
authors.initials: K
authors.lastname: Pingali
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Muzzio
mesh_terms: D000082:Acetaminophen / Q000737:chemistry*; D018712:Analgesics, Non-Narcotic / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D005079:Excipients / Q000737:chemistry; D008153:Lubrication; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D018712:Analgesics, Non-Narcotic; D005079:Excipients; D000082:Acetaminophen; D002482:Cellulose; C109691:microcrystalline cellulose