Effect of compression speed on the relationship between normalised solid fraction and mechanical properties of compacts

Holman, L.E.; Leuenberger, Hans

doi:10.1016/0378-5173(89)90268-8

Cited by 11 publications

(3 citation statements)

References 7 publications

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“…A number of researchers have used several different approaches to determine the effects of changes in punch velocity on the compaction properties of various materials and formulations. Several researchers (22,23) examined the effect of machine speed on the compaction behavior of various directly compressible materials. These workers found that compact strength increased as machine speed decreased for viscoelastic materials (such as pregelatinized starch and microcrystalline cellulose), but had little effect on brittle materials (such as dicalcium phosphate and lactose).…”

Section: Introductionmentioning

confidence: 99%

The Effect of Compression and Decompression Speed on the Mechanical Strength of Compacts

Ruegger

Çelik²

2000

Pharmaceutical Development and Technology

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The purpose of this work was to investigate the effect of punch speed on the compaction properties of pharmaceutical powders; in particular, to separate out differences between the effect of the compression and decompression events. Tablets were prepared using an integrated compaction research system. Various "sawtooth" punch profiles were followed to compare the effects of different punch speeds on the crushing strength of the resulting tablets. The loading and unloading speeds were varied independently of one another. In general, when the compression speed was equal to the decompression speed, the tablet crushing strength was observed to decrease as the punch velocity increased. When the compression speed was greater than or less than the decompression speed, the results varied, depending on the material undergoing compaction. Reduction of the unloading speed from 300 to 10 mm/sec for pregelatinized starch and microcrystalline cellulose produced a significant increase in crushing strength, whereas no significant increase in crushing strength was observed until the loading speed was reduced to 10 mm/sec. Reduction of the unloading speed had a similar effect on the direct compression (DC) ibuprofen, however, even greater improvement in the crushing strength was observed when the loading speed was reduced. No improvement in the DC acetaminophen tablets was observed when the unloading speed was reduced, however, a significant increase in crushing strength was produced when the rate of loading was reduced. This work showed that the strength of tablets can be improved and some tableting problems such as capping can be minimized or prevented by modifying the rates of loading/unloading.

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Section: Introductionmentioning

confidence: 99%

The Effect of Compression and Decompression Speed on the Mechanical Strength of Compacts

Ruegger

Çelik²

2000

Pharmaceutical Development and Technology

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“…In the range used in this study, compression speed appears to have no clear systematic effect on the breaking force of lactose, glucose and mannitol tablets. In the study of Holman & Leuenberger (1989), all compression parameters for lactose tablets were also essentially insensitive to the changing speeds of compression. On the other hand, Armstrong & Palfrey (1989) (b) and mannitol (c) tablets according to compression force (n = 40).…”

Section: Breaking Force Of Tabletsmentioning

confidence: 96%

Compression of Lactose, Glucose and Mannitol Granules

Juppo

Kervinen

Yliruusi

et al. 1995

Journal of Pharmacy and Pharmacology

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The effect of the amount of granulation liquid, compression speed and maximum compression force on then compressibility and compactibility of lactose, glucose and mannitol granules was studied. The porosity based on the geometrical shape and the uniformity of weight of tablets was also studied. Lactose and mannitol granules showed a greater compressibility than glucose granules. Mannitol granules produced the hardest tablets and lactose and glucose the weakest. The change in the amount of granulation liquid caused changes both in the granule porosity and in the amount of binder; this was attributed to differences in tablet strength. All parameters studied were relatively insensitive to changing speeds of compression in the range used, except for the breaking force of mannitol tablets, which was greatest with the lowest speed of compression. All granule masses showed a relatively good continuous flow suitable for table production. Tablets compressed from lactose granules had the best uniformity of weight of the tablets studied.

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“…Speed's effect on deformation and densification properties is generally known for plastically and viscoelastically deforming materials. [5][6][7][8][9][10][11][12] Examples for this are microcrystalline cellulose (MCC), 9 polyethylene glycol, 10-11 hydroxypropyl methylcellulose (HPMC), 12 and polystyrene. 13 Little effect has been found for materials that predominantly fracture and show brittle compaction behavior-for instance, dicalcium phosphate dihydrate (DCPD), lactose, or DC calcium lactate.…”

Section: Introductionmentioning

confidence: 99%

The 3-D model: Does time plasticity represent the influence of tableting speed?

Picker

2003

AAPS PharmSciTech

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The objective of this study is to test the hypothesis that time plasticity (parameter d from 3-D modeling) is influenced by tableting speed. Tablets were produced at different maximum relative densities (rho(rel, max)) on an instrumented eccentric tableting machine and on a linear rotary tableting machine replicator. Some 3-D data plots were prepared using pressure, normalized time, and porosity according to Heckel. After fitting of a twisted plane, the resulting parameters were analyzed in a 3-D parameter plot. The materials used were dicalcium phosphate dihydrate (DCPD), spray-dried lactose, microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), kappa-carrageenan (CAR), and theophylline monohydrate (TheoM). The results show that tableting speed especially influences the parameter d (time plasticity) of the 3-D model for plastically and viscoelastically deforming materials such as MCC, HPMC, CAR, and TheoM. For more plastically deforming materials such as MCC, HPMC, and TheoM, a subtle influence on omega is also visible. The stages of higher densification are affected more than the stages of lower densification. Brittle materials such as DCPD exhibit no influence of tableting speed. The influence of speed on spray-dried lactose is minor. The results are valid for data obtained from an eccentric tableting machine and also for data from a linear rotary tableting machine replicator. Thus, the empirically derived parameter time plasticity d really represents the influence of time.

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Effect of compression speed on the relationship between normalised solid fraction and mechanical properties of compacts

Cited by 11 publications

References 7 publications

The Effect of Compression and Decompression Speed on the Mechanical Strength of Compacts

The Effect of Compression and Decompression Speed on the Mechanical Strength of Compacts

Compression of Lactose, Glucose and Mannitol Granules

The 3-D model: Does time plasticity represent the influence of tableting speed?

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