An experimental investigation of temperature rise during compaction of pharmaceutical powders.
During pharmaceutical powder compaction, temperature rise in the compressed powder can affect physiochemical properties of the powder, such as thermal degradation and change in crystallinity. Thus, it is of practical importance to understand the effect of process conditions and material properties on the thermal response of pharmaceutical formulations during compaction. The aim of this study was to examine the temperature rise of pharmaceutical powders during tableting, in particular, to explore how the temperature rise depends on material properties, compression speed and tablet shape. Three grades of microcrystalline cellulose (MCC) were considered: MCC Avicel pH 101, MCC Avicel pH 102 and MCC DG. These powders were compressed using a compaction simulator at various compaction speeds (10-500mm/s). Flat faced, shallow convex and normal convex tablets were produced and temperature distributions on the surface of theses tablets upon ejection were examined using an infrared thermoviewer. It was found that an increase in the compaction speed led to an increase in the average surface temperature. A higher surface temperature was induced when the powder was compressed into a tablet with larger surface curvature. This was primarily due to the increasing degree of powder deformation (i.e. the volume reduction) and the effect of interparticule/wall friction.
Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK. Electronic address: a.krok@surrey.ac.uk.
Alexander
A
Krok
Pharmaceutical Development, AstraZeneca, Macclesfield, Cheshire SK10 2NA, UK.
Andreja
A
Mirtic
Pharmaceutical Development, AstraZeneca, Macclesfield, Cheshire SK10 2NA, UK.
Gavin K
GK
Reynolds
Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK.
Serena
S
Schiano
Pharmaceutical Development, AstraZeneca, Macclesfield, Cheshire SK10 2NA, UK.
Ron
R
Roberts
Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK. Electronic address: c.y.wu@surrey.ac.uk.
Chuan-Yu
CY
Wu
D002482:Cellulose / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003460:Crystallization; D005079:Excipients / Q000737:chemistry*; D011208:Powders; D013607:Tablets; D013696:Temperature
D005079:Excipients; D011208:Powders; D013607:Tablets; D002482:Cellulose; C109691:microcrystalline cellulose
Microcrystalline cellulose; Powder compaction; Tabletting; Temperature rise