Critical Considerations for the Qualitative and Quantitative Determination of Process‐Induced Disorder in Crystalline Solids

Newman, Ann; Zografi, George

doi:10.1002/jps.23930

Cited by 49 publications

(28 citation statements)

References 48 publications

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“…The physical nature of partially disordered particles has been the object of considerable discussion in the literature (Bordet et al, 2016; Dujardin et al, 2013; Luisi et al, 2012; Newman and Zografi, 2014; Pazesh et al, 2017) and it has been proposed that they may be composed of crystallites surrounded by crystal defects or alternatively be composed of amorphous and crystalline domains, i.e. a two-phase particle.…”

Section: Discussionmentioning

confidence: 99%

“…The physical nature of mechanically disordered particles has been the object of considerable discussion in the literature and it is proposed (Dujardin et al, 2013; Luisi et al, 2012; Newman and Zografi, 2014) that they may be composed of crystallites surrounded by crystal defects (one-state model) or consist of amorphous and crystalline domains (two-state model) or a combination thereof. By studying lactose particles partially disordered by milling, we reported (Badal Tejedor et al, 2017) that the particles had a surface which approximated the nature of the surface of fully amorphous particles prepared by spray-drying.…”

Section: Introductionmentioning

confidence: 99%

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Atypical compaction behaviour of disordered lactose explained by a shift in type of compact fracture pattern

Pazesh

Persson

Alderborn

2019

International Journal of Pharmaceutics: X

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The objective was to investigate tabletability and compactibility for compacts of a series of α-lactose monohydrate powders with different degree of disorder. Regarding the tabletability, the powders of high degree of disorder displayed similar behaviour that deviated markedly from the behaviour of the crystalline powders and the milled powder of modest degree of disorder. The Ryshkewitch-Duckworth equation, describing compactibility, was nearly linear for the crystalline powders, while for the disordered powders the model failed to describe the relationships, i.e. the disordered powders were characterised by a plateau in the Ryshkewitch-Duckworth plots over a relatively wide range of compact porosities. It was concluded that the difference in compaction behaviour of the milled particles compared to the crystalline powders was primarily explained by the increased particle plasticity of the disordered particles. The plateau in the Ryshkewitch-Duckworth plots obtained for the disordered powders was explained by a change in the fracture behaviour of the compacts, from an around grain to an across grain fracture pattern. This implied that the disordered particles can be described as a type of core-shell particles with an amorphous shell and a defective crystalline core.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Atypical compaction behaviour of disordered lactose explained by a shift in type of compact fracture pattern

Pazesh

Persson

Alderborn

2019

International Journal of Pharmaceutics: X

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“…Milling is one the most common particle size reduction step. The effect of milling parameters, such as milling frequency, impact velocity, milling time on particle bulk and surface properties, is well documented in the literature Adrjanowicz et al, 2011;Forcino et al, 2010;Vegt et al, 2009;Shariare et al, 2011;Perkins et al, 2009;Kwan et al, 2004;Kwan et al, 2003;Leleux and Williams, 2014;Newman and Zografi, 2014). Kwan et al investigated the effect of milling frequency and propensity of breakage for microcrystalline cellulose and α-lactose monohydrate.…”

Section: Introductionmentioning

confidence: 98%

Effect of milling temperatures on surface area, surface energy and cohesion of pharmaceutical powders

Shah

Wang

Olusanmi

et al. 2015

International Journal of Pharmaceutics

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Particle bulk and surface properties are influenced by the powder processing routes. This study demonstrates the effect of milling temperatures on the particle surface properties, particularly surface energy and surface area, and ultimately on powder cohesion. An active pharmaceutical ingredient (API) of industrial relevance (brivanib alaninate, BA) was used to demonstrate the effect of two different, but most commonly used milling temperatures (cryogenic vs. ambient). The surface energy of powders milled at both cryogenic and room temperatures increased with increasing milling cycles. The increase in surface energy could be related to the generation of surface amorphous regions. Cohesion for both cryogenic and room temperature milled powders was measured and found to increase with increasing milling cycles. For cryogenic milling, BA had a surface area ∼ 5× higher than the one obtained at room temperature. This was due to the brittle nature of this compound at cryogenic temperature. By decoupling average contributions of surface area and surface energy on cohesion by salinization post-milling, the average contribution of surface energy on cohesion for powders milled at room temperature was 83% and 55% at cryogenic temperature.

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“…Even if a sample is 10% -20% amorphous, the halo may not be evident and cannot be separated completely with diffraction peaks. PXRD is useful for the detection of a small amount of crystalline, but it is difficult to obtain reliable results for samples with low amorphous content to access accurate amorphous content [167]. PXRD has been employed in investigating the crystallinity of αlactose monohydrate and comparing it to spray-dried lactose which lacks crystalline long-range order [168].…”

Section: Solid-state Characterizationmentioning

confidence: 99%

Physical stability of dry powder inhaler formulations

Shetty

Cipolla

Park

et al. 2019

Expert Opinion on Drug Delivery

114

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Introduction: Dry powder inhalers (DPIs) are popular for pulmonary drug delivery. Various techniques have been employed to produce inhalation drug particles and improve the delivery efficiency of DPI formulations. Physical stability of these DPI formulations is critical to ensure the delivery of a reproducible dose to the airways over the shelf-life.Areas covered: This review focuses on the impact of solid-state stability on aerosolization performance of DPI drug particles manufactured by powder production approaches and particle engineering techniques. It also highlights the different analytical tools that can be used to characterize the physical instability originating from production and storage.Expert opinion: A majority of the DPI literature focuses on the effects of physico-chemical properties such as size, morphology and density on aerosolization. While little has been reported on the physical stability, particularly the stability of engineered drug particles for use in DPIs. Literature data have shown that different particle engineering methods and storage conditions may cause physical instability of dry powders for inhalation and can significantly change the aerosol performance. A systematic examination of physical instability mechanisms in DPI formulations is necessary during formulation development in order to select the optimum formulation with satisfactory stability. In addition, the use of appropriate characterization tools are critical to detect and understand physical instability during the development of DPI formulations.

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Critical Considerations for the Qualitative and Quantitative Determination of Process‐Induced Disorder in Crystalline Solids

Cited by 49 publications

References 48 publications

Atypical compaction behaviour of disordered lactose explained by a shift in type of compact fracture pattern

Atypical compaction behaviour of disordered lactose explained by a shift in type of compact fracture pattern

Effect of milling temperatures on surface area, surface energy and cohesion of pharmaceutical powders

Physical stability of dry powder inhaler formulations

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