Effect of punch tip geometry and embossment on the punch tip adherence of a model ibuprofen formulation.
The sticking of a model ibuprofen-lactose formulation with respect to compaction force, punch tip geometry and punch tip embossment was assessed. Compaction was performed at 10, 25 or 40 kN using an instrumented single-punch tablet press. Three sets of 'normal' concave punches were used to evaluate the influence of punch curvature and diameter. The punches were 10, 11 and 12 mm in diameter, respectively. The 10-mm punch was embossed with a letter 'A' logo to assess the influence of an embossment on sticking. Flat-faced punches (12.5 mm) were used for comparison with the concave tooling. Surface profiles (Taylor Hobson Talysurf 120) of the upper punch faces were obtained to evaluate the surface quality of the tooling used. Following compaction, ibuprofen attached to the upper punch face was quantified by spectroscopy. Increasing punch curvature from flat-faced punches to concave decreased sticking. Altering punch diameter of the concave punches had no effect on sticking when expressed as microg mm(-2). The embossed letter 'A' logo increased sticking considerably owing to the probable concentration of shear stresses at the lateral faces of the embossed logo.
Roberts
Matthew
M
School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
Ford
James L
JL
MacLeod
Graeme S
GS
Fell
John T
JT
Smith
George W
GW
Rowe
Philip H
PH
Dyas
A Mark
AM
D000268:Adhesiveness; D019245:Compressive Strength; D007052:Ibuprofen / Q000737:chemistry*; D007785:Lactose / Q000737:chemistry; D013607:Tablets / Q000737:chemistry*; D013678:Technology, Pharmaceutical
D013607:Tablets; D007785:Lactose; D007052:Ibuprofen