The variation of the surface topography of granules under compression with degree of binder addition

Stanley-Wood, N.G.; Shubair, M. S.

doi:10.1016/0032-5910(80)87009-4

Cited by 10 publications

(4 citation statements)

References 14 publications

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“…Dibasic calcium phosphate dihydrate undergoes extensive fragmentation during compression as demonstrated by large increase of surface area after compression 35,23,7,18 , a high strength isotropy ratio 23 , a very small effect of lubricants on tablets strength 22,36,37,23 and absence of time dependent effects 20,25,38 In this study, Dibasic calcium phosphate  tablets were degassed at 20ºC for 18 hours. Concentrations of 0.5% and 1.0% of magnesium stearate were used as lubricant.…”

Section: Dibasic Calcium Phosphate Dihydrate (Emcompress ® )mentioning

confidence: 99%

Effect of the Lubricant Magnesium Stearate on Changes of Specific Surface Area of Directly Compressible Powders under Compression = تأثير المشحم ( مغنيسيوم ستياريت ) على تغيرات المساحة السطحية الخاصة بالمساحيق القابلة للكبس أثناء عملية الكبس

Hamad¹,

Arida²,

Al-Tabakha³

2015

JJPS

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During compression, powders fragment, plastically deform, and/or may behave both ways. Different profiles of specific surface area changes have been shown in several studies for many powders. In this study, the effect of a lubricant on the specific surface area of a powder was studied during the consolidation process of the powder as an attempt to clarify the behavior of powders under compression. Changes in specific surface areas of Starch (Rice starch), cellulose (Avicel ® PH102), spray dried lactose (Zeparox ®), and dibasic calcium phosphate (Emcompress ®) were studied using gas adsorption technique. Magnesium stearate was used as a lubricant. Specific surface area of plastically deforming materials; cellulose, and starch was clearly affected by the addition of lubricants. Spray dried lactose combined both fragmenting and plastically deforming behavior in its consolidation under compression and its specific surface area was slightly affected by the addition of lubricant. Specific surface area of fragmenting material; Dibasic calcium phosphate was not affected by the addition of a lubricant.

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Section: Dibasic Calcium Phosphate Dihydrate (Emcompress ® )mentioning

confidence: 99%

Effect of the Lubricant Magnesium Stearate on Changes of Specific Surface Area of Directly Compressible Powders under Compression = تأثير المشحم ( مغنيسيوم ستياريت ) على تغيرات المساحة السطحية الخاصة بالمساحيق القابلة للكبس أثناء عملية الكبس

Hamad¹,

Arida²,

Al-Tabakha³

2015

JJPS

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“…This is especially obvious for strongly fragmenting materials (30). In the case of solid bridges, the term corresponds to the true interparticulate contact area, while for intermolecular forces the term is more diffuicult to define.…”

Section: Bonding Surface Areamentioning

confidence: 99%

“…The result could probably be explained by a reduction in particle fragmentation and crack formation in the systems containing lubricant additions. Considering the even more complex nature of most pharmaceutical materials used in some reported studies (8,11,29,30,77) it is questionable whether the interpretations suggested, purporting relatively high bonding surface areas (1 1, 29, 30, 77), are justified solely on the basis of previously published experimental data. The results obtained demonstrate the problems involved when investigating the compaction behaviour of pharmaceutical materials.…”

Section: Relations Between Tablet Surface Area and Bonding Surface Areamentioning

confidence: 99%

Bonding Surface area and Bonding Mechanism-Two Important Factors fir the Understanding of Powder Comparability

Nyström

Alderborn

Duberg

et al. 1993

Drug Development and Industrial Pharmacy

205

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Two factors could be regarded as primary factors for the compactability of powders: the dominating bond mechanism and the surface area over which these bonds are active. Owing to considerable experimental difficulties, these factors have not been evaluated in any detail for pharmaceutical materials. Instead, more indirect, secondary factors are normally studied and used for correlations with tablet strength. Such secondary factors particle size, shape and surface texture. Also the importance of volume reduction mechanisms, i.e. elastic deformation, plastic deformation and particle fragmentation have been studied in detail.For the investigation of dominating bond mechanisms and estimation of the magnitude of the surface area of the solids involved in interparticulate attraction in compacts several pharmaceutical excipients representing both plastically deforming materials (sodium chloride, Avicel@ PH 101, Sta-Rx 1500@, and sodium 2143

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“…This indicates that the powder particles aggregated to become a compacted solid. Stanley-Wood and Shubair [32] suggested that the loss of surface area was due to the formation of granule-granule or particle-particle bonds. However, the S BET of the compacts increased from 109 m 2 /g to 198 m 2 /g when the compression pressure increased from 20 MPa to 40 MPa, which is considered the effect of particle fragmentation.…”

Section: Resultsmentioning

confidence: 99%

Contact-Hardening Behavior of Calcium Silicate Hydrate Powders

et al. 2018

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Calcium silicate hydrate (C-S-H) synthesized by a hydrothermal process from lime and siliceous materials was oven-dried and compressed into compacts. The microstructure and compaction properties of the resulting powders were characterized. The results show that the powders containing an amorphous structure become hardened compacts immediately after compression. Compacts with high strength but a relatively lower bulk density were produced. Amorphous C-S-H plays a key role in the bonding formation during powder compaction. According to the Heckel plots, particle rearrangement and plastic deformation were involved in the compaction of C-S-H powders. Point contact between C-S-H particles due to particle rearrangement dominates at a low compression pressure (i.e., <20 MPa). Van der Waals forces and hydrogen bonding are the main bonding types. Plastic deformation occurs at a higher compression pressure (i.e., >60 MPa), which results in surface contact. Consequently, a solid bridge forms, and the strength of compacts increases rapidly. These findings provide novel insight into the utilization of materials containing amorphous calcium silicate hydrate.

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The variation of the surface topography of granules under compression with degree of binder addition

Cited by 10 publications

References 14 publications

Bonding Surface area and Bonding Mechanism-Two Important Factors fir the Understanding of Powder Comparability

Contact-Hardening Behavior of Calcium Silicate Hydrate Powders

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