The effect of speed of compression on the properties of compacts.
type: CreativeWork
description: A high speed hydraulic press has been developed into a computer controlled high speed compression Simulator, capable of reproducing displacement time profiles seen on any production tabletting machine. The system has been validated to monitor punch displacements to ?12pm and loads to ?O.05% of full scale. Confidence in the results obtained using the Simulator were enhanced by comparison with other operational Simulators. The established Simulator was then used to investigate the effects of compression on ibuprofen. Ibuprofen was found to consolidate mainly by plastic deformation with a lesser contribution from the melting of asperities. A significant amount of pressure induced melting and subsequent fusion bonding occurred at higher pressures. Ibuprofen was found to be sensitive to the magnitude and rate of application of the compression pressure. The extent of plastic flow exhibited by ibuprofen during compression was, found to decrease as the compression speed increased. Lamination and capping of ibuprofen compacts at high compression speeds was considered to be due to a combination of air entrapment and the inability of the compact to withstand the stresses of decompression. When ibuprofen was mixed with a second material and compressed, the consolidation mechanism and properties of the compacts formed were found to follow complex relationships. The relationships were dependant on the proportion of each material and the speed of compression. For ibuprofen microcrystalline cellulose mixtures positive interactions were considered to occur due to bonding between the two materials. For ibuprofen and lactose mixtures the interactions observed were considered to be a balance between the plastic deformation by the ibuprofen relieving the applied load preventing the cri tical force required for fracture of the lactose being attained, and the lactose fragments bearing the applied load reducing plastic flow by ibuprofen. The Simulator was then employed to investigate diffe…
abstract: A high speed hydraulic press has been developed into a computer controlled high speed compression Simulator, capable of reproducing displacement time profiles seen on any production tabletting machine. The system has been validated to monitor punch displacements to ?12pm and loads to ?O.05% of full scale. Confidence in the results obtained using the Simulator were enhanced by comparison with other operational Simulators. The established Simulator was then used to investigate the effects of compression on ibuprofen. Ibuprofen was found to consolidate mainly by plastic deformation with a lesser contribution from the melting of asperities. A significant amount of pressure induced melting and subsequent fusion bonding occurred at higher pressures. Ibuprofen was found to be sensitive to the magnitude and rate of application of the compression pressure. The extent of plastic flow exhibited by ibuprofen during compression was, found to decrease as the compression speed increased. Lamination and capping of ibuprofen compacts at high compression speeds was considered to be due to a combination of air entrapment and the inability of the compact to withstand the stresses of decompression. When ibuprofen was mixed with a second material and compressed, the consolidation mechanism and properties of the compacts formed were found to follow complex relationships. The relationships were dependant on the proportion of each material and the speed of compression. For ibuprofen microcrystalline cellulose mixtures positive interactions were considered to occur due to bonding between the two materials. For ibuprofen and lactose mixtures the interactions observed were considered to be a balance between the plastic deformation by the ibuprofen relieving the applied load preventing the cri tical force required for fracture of the lactose being attained, and the lactose fragments bearing the applied load reducing plastic flow by ibuprofen. The Simulator was then employed to investigate diffe…
author: Bateman, SD
keywords: RM Therapeutics. Pharmacology
date published: 1988-01
date modified: 2026-07-24T06:30:03Z
provider: Liverpool Jon Moores University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Liverpool John Moores University

PropertyValue
property ID: DOI
value: 10.24377/LJMU.t.00004892