Factorial designed experiment to study the effects of excipients on the mechanical properties of pellets.
The aim of this work was to determine the effects of formulation factors on the mechanical properties of pellets produced by the process of extrusion and spheronisation. A range of properties from a simple fracture load to detailed load/displacement curves were used to study the effects of the levels of lactose monohydrate and glyceryl monostearate on the mechanical properties of pellets in terms of their surface tensile strength, pellet deformability and linear strain. A series of independent 2(2)-factorial designs were employed to establish the relationships between composition of the formulations and pellet properties, whereby the concept of an excess variable was explored. It was found that the spheronisation aid used, microcrystalline cellulose, is the domineering factor in most mechanical properties studied, except for the surface tensile strength, which decreased significantly with an increase in glyceryl monostearate concentration. The change in binder liquid from water to a water/ethanol mixture further changed the behaviour of the systems significantly. The assumption of an excess variable being less critical for the statistical outcome of a factorial experiment has not been found feasible for the systems studied.
Bashaiwoldu
Abraham B
AB
School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK.
Podczeck
Fridrun
F
Newton
J Michael
JM
D002482:Cellulose / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004343:Drug Implants; D000431:Ethanol / Q000008:administration & dosage; D005079:Excipients / Q000737:chemistry*; D005990:Glycerol / Q000008:administration & dosage; D007785:Lactose / Q000008:administration & dosage; D019563:Mechanics; D012107:Research Design; D013718:Tensile Strength
D004343:Drug Implants; D005079:Excipients; D000431:Ethanol; D002482:Cellulose; D007785:Lactose; C109691:microcrystalline cellulose; D005990:Glycerol