Impact breakage of acicular crystals

Saifoori, Saba; Goh, Wei-Pin; Ali, Muzammil; Ghadiri, Mojtaba

doi:10.1016/j.powtec.2019.11.061

Cited by 4 publications

(8 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After percolation at inlet pressure of 4 bar (ΔP b =3.78 bar) the F curve shifts significantly outside this range confirming that the observed PSD changes are significant. In addition this shows the changes are due to the percolation process rather than fragmentation of crystals in the particle sizer as observed by Saifoori et al (27).…”

Section: Particle Size Analysissupporting

confidence: 68%

“…The Morphologi G3 has found significant application on a variety of different particle systems within the particle sizing and shape characterisation fields; typically with mineralogical and pharmaceutical based systems ( 26 ). To minimise agglomeration, stacking and breakage ( 27 ) a 13 mm 3 sample was dispersed by a 0.5 bar ‘pulse’ of nitrogen to deposit the material over a 50 mm diameter circle. To balance capturing crystal details and maintaining good depth resolution the 5x and 10x magnification lenses were utilised according to the crystal size.…”

Section: Materials and Methodologymentioning

confidence: 99%

“…In addition this shows the changes are due to the percolation process rather than fragmentation of crystals in the particle sizer as observed by Saifoori et al . ( 27 ).…”

Section: Materials and Methodologymentioning

confidence: 99%

See 2 more Smart Citations

On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous Percolation

et al. 2020

View full text Add to dashboard Cite

Purpose This work details experimental observations on the effect of liquid flow percolating through packed beds of crystals to elucidate how the filtration pressure severely alters the size distribution and crystal shape. Pressure filtration is widely used in the pharmaceutical industry, and frequently results in undesired size distribution changes that hinder further processing. Methods The percolation methodology presented fixes fluid flow through a bed of crystals, resulting in a pressure over the bed. X-ray computed tomography (XCT) provided detailed observations of the bed structure. Detailed 2D particle size data was obtained using automated microscopy and was analysed using an in-house developed tool. Results Crystal breakage is observed when the applied pressure exceeds a critical pressure: 0.5–1 bar for ibuprofen, 1–2 bar for β-L glutamic acid (LGA) and 2–2.5 bar for para amino benzoic acid (PABA). X-ray computed tomography showed significant changes in bed density under the applied pressure. Size analysis and microscope observations showed two modes of breakage: (i) snapping of long crystals and (ii) shattering of crystals. Conclusion LGA and PABA have a similar breakage strength (50 MPa), ibuprofen is significantly weaker (9 MPa). Available breakage strength data may be correlated to the volumetric Gibbs free energy. Data from 12 and 35 mm bed diameters compares well to literature data in a 80 mm filter; the smaller, easy to operate percolation unit is a versatile tool to assess crystal breakage in filtration operations.

show abstract

Section: Particle Size Analysissupporting

confidence: 68%

Section: Materials and Methodologymentioning

confidence: 99%

See 1 more Smart Citation

On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous Percolation

et al. 2020

View full text Add to dashboard Cite

show abstract

“…There exists a transition point at around 2 barg above which the changes in particle length and width between each pair of consecutive pressures become more gradual. These results show that unlike other acicular crystals, such as -glutamic acid (Saifoori et al, 2019), carbamazepine dihydrate crystals do break in a noticeable degree along both their length and width. Though not to the same extent as the particle length, there is a substantial reduction in the particle width from 180 to 100 m (~44%).…”

Section: Extent Of Breakagementioning

confidence: 68%

Assessment of impact breakage of carbamazepine dihydrate due to aerodynamic dispersion

Goh

Ali

Sinha

et al. 2019

International Journal of Pharmaceutics

Self Cite

View full text Add to dashboard Cite

Acicular crystals are very common in pharmaceutical manufacturing. They are very prone to breakage, causing unwanted particle size degradation and problems such as segregation and lump formation. We investigate the breakage pattern of carbamazepine dihydrate, an acicular and platy crystal with cleavage planes. It readily undergoes attrition during isolation and drying stage, causing processing difficulties. We use the aerodynamic dispersion of a very small quantity of powder sample to induce breakage by applying a pulse of pressurised air. The dispersion unit of Morphologi G3 is used for this purpose. The broken particles settle in a chamber and are subsequently analysed using the built-in image analysis software. The shift in the particle size and shape distributions is quantified through which the extent of breakage is determined as a function of the dispersion pressure. The analysis reveals a change of breakage mechanism as the dispersion pressure is increased from primarily snapping along the crystal length to one in which chipping has also a notable contribution. The breakage data are analysed using a modified impact-based breakage model and the breakability index of the carbamazepine dihydrate is determined for the two breakage regimes. The method provides a quick and easy testing of particle breakability, a useful tool for assessing attrition in process plant and grindability in milling operations.

show abstract

“…In these studies, the particles were accelerated towards a target to facilitate breakage. [46][47][48] Higher impact velocities resulted in considerable change of crystal size with breakage. From Fig.…”

Section: Introductionmentioning

confidence: 99%

Understanding stress-induced disorder and breakage in organic crystals: beyond crystal structure anisotropy

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Impact breakage of acicular crystals

Cited by 4 publications

References 37 publications

On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous Percolation

On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous Percolation

Assessment of impact breakage of carbamazepine dihydrate due to aerodynamic dispersion

Understanding stress-induced disorder and breakage in organic crystals: beyond crystal structure anisotropy

Contact Info

Product

Resources

About