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Shi L, Sun CC. Understanding the roles of compaction pressure and crystal hardness on powder tabletability through bonding area - Bonding strength interplay. Int J Pharm 2024; 659:124253. [PMID: 38788972 DOI: 10.1016/j.ijpharm.2024.124253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/29/2024] [Accepted: 05/20/2024] [Indexed: 05/26/2024]
Abstract
Bonding area (BA) and bonding strength (BS) interplay dictates tensile strength of a tablet and, hence, tabletability. Using a series of alkali halides with mechanical properties spanning more than one order of magnitude, the role of compaction pressure and mechanical properties on tabletability is systematically investigated and explained using the BA-BS interplay. Results reveal that BA dominates the BA-BS interplay at low pressures, where more plastic powders attain higher tensile strength due to larger BA. In contrast, BS dominates the interplay at high pressures, when difference in BA between powders is minimized. Under the typical compaction pressures of 100-300 MPa, tablet tensile strength is the highest for materials with intermediate hardness, or plasticity, due to an optimal BA-BS interplay.
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Affiliation(s)
- Limin Shi
- Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota, USA
| | - Changquan Calvin Sun
- Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota, USA.
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2
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Boudina I, Delalonde M, Koegel L, Maraval I, Forestier-Chiron N, Domingo R, Ricci J, Sharkawi T, Rondet E. Mechanical approach for the evaluation of the crispiness of food granular products. J Texture Stud 2023; 54:633-645. [PMID: 37264445 DOI: 10.1111/jtxs.12764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 06/03/2023]
Abstract
Crispiness of food products is a key parameter for consumer acceptance. Available methods to evaluate this attribute are subjective and have limitations. They are particularly difficult to implement when granular products are considered. The present study aims to provide a physical characterization of the crispiness of food granular products (gari and grinded corn flakes) based on the compression cycle modeling and the determination of the Py (yield pressure) parameter of the Heckel model. High Py values attributed to the brittle behavior, are indicative of product crispiness. Furthermore, Py parameter showed sensitivity to the plasticizing effect of water. This developed physical method was validated through sensory analysis and acoustic measurements which are both considered as reference methods for crispiness evaluation. The brittle/plastic behavior attributed to crispy/non crispy products respectively was confirmed through image analysis using X-ray microcomputed tomography. The latter made it possible to distinguish the brittle from the plastic behavior through the particle size distribution evolution. This work suggests that the Py value is a relevant indicator for the crispiness evaluation of granular products. This physical characterization is expected to contribute in food engineering as an alternative method for granular products crispiness in a simpler and a more objective way.
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Affiliation(s)
- Imen Boudina
- ICGM, CNRS, ENSCM, Université Montpellier, Montpellier, France
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Michèle Delalonde
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Laurène Koegel
- ICGM, CNRS, ENSCM, Université Montpellier, Montpellier, France
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Isabelle Maraval
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Nelly Forestier-Chiron
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Romain Domingo
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Julien Ricci
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
| | - Tahmer Sharkawi
- ICGM, CNRS, ENSCM, Université Montpellier, Montpellier, France
| | - Eric Rondet
- QualiSud, Université de Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de la Réunion, Montpellier, France
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How can single particle compression and nanoindentation contribute to the understanding of pharmaceutical powder compression? Eur J Pharm Biopharm 2021; 165:203-218. [PMID: 34010689 DOI: 10.1016/j.ejpb.2021.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/07/2021] [Accepted: 05/09/2021] [Indexed: 11/23/2022]
Abstract
The deformation behaviour of a powder and, thus, of the individual particles is a crucial parameter in powder compaction and affects powder compressibility and compactibility. The classical approach for the characterization of the deformation behaviour is the performance of powder compression experiments combined with the application of mathematical models, such as the Heckel-Model, for the derivation of characteristic compression parameters. However, the correlation of these parameters with the deformation behaviour is physically often not well understood. Single particle compression and nanoindentation enables the in-depth investigation of the deformation behaviour of particulate materials. In this study, single particle compression experiments were performed for the characterization of the deformation behaviour of common pharmaceutical excipients and active pharmaceutical ingredients (APIs) with various, irregular particle morphologies of industrial relevance and the findings are compared with the results from powder compression. The technique was found useful for the characterization and clarification of the qualitative deformation behaviour. However, the derivation of a quantitative functional relationship between single particle deformation behavior and powder compression is limited. Nanoindentation was performed as complementary technique for the characterization of the micromechanical behavior of the APIs. A linear relationship between median indentation hardness and material densification strength as characteristic parameter derived by in-die powder compression analysis is found.
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Chen Y, Powell CT, Yu L. Tensile Fracture of Molecular Glasses Studied by Differential Scanning Calorimetry: Reduction of Heat Capacity by Lateral Constraint. J Phys Chem B 2017; 121:444-449. [DOI: 10.1021/acs.jpcb.6b11347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yinshan Chen
- School of Pharmacy, ‡Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - C. Travis Powell
- School of Pharmacy, ‡Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Lian Yu
- School of Pharmacy, ‡Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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Singaraju AB, Nguyen K, Jain A, Haware RV, Stevens LL. Aggregate Elasticity, Crystal Structure, and Tableting Performance for p-Aminobenzoic Acid and a Series of Its Benzoate Esters. Mol Pharm 2016; 13:3794-3806. [PMID: 27723351 DOI: 10.1021/acs.molpharmaceut.6b00598] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The tableting performance for p-aminobenzoic acid (PABA) and a series of its benzoate esters with increasing alkyl chain length (methyl-, ethyl-, and n-butyl) was determined over a broad range of compaction pressures. The crystalline structure of methyl benzoate (Me-PABA) exhibits no slip systems and does not form viable compacts under any compaction pressure. The ethyl (Et-PABA) and n-butyl (Bu-PABA) esters each have a similar, corrugated-layer structure that displays a prominent slip plane and improves material plasticity at low compaction pressure. The compact tensile strength for Et-PABA is superior to that for Bu-PABA; however, neither material achieved a tensile strength greater than 2 MPa over the compression range studied. Complementary studies with powder Brillouin light scattering (BLS) show the maxima of the shear wave, acoustic frequency distribution red shift in an order consistent with both the observed tabletability and attachment energy calculations. Moreover, zero-porosity aggregate elastic moduli are determined for each material using the average acoustic frequency obtained from specific characteristics of the powder BLS spectra. The Young's moduli for Et- and Bu-PABA is significantly reduced relative to PABA and Me-PABA, and this reduction is further evident in tablet compressibility plots. PABA, however, is distinct with high elastic isotropy as interpreted from the narrow and well-defined powder BLS frequency distributions for both the shear and compressional acoustic modes. The acoustic isotropy is consistent with the quasi-isotropic distribution of hydrogen bonding for PABA. At low compaction pressure, PABA tablets display the lowest tensile strength of the series; however, above a compaction pressure of ca. 70 MPa PABA tablet tensile strength continues to increase while that for Et- and Bu-PABA plateaus. PABA displays lower plasticity relative to either ester, and this is consistent with its crystalline structure and high yield pressure determined from in-die Heckel analysis. Overall the complementary approach of using both structural and the acoustic inputs uniquely provided from powder BLS is anticipated to expand our comprehension of the structure-mechanics relationship and its role in tableting performance.
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Affiliation(s)
- Aditya B Singaraju
- Division of Pharmaceutics and Translational Therapeutics, College of Pharmacy, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Kyle Nguyen
- Division of Pharmaceutics and Translational Therapeutics, College of Pharmacy, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Abhay Jain
- Division of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University , Buies Creek, North Carolina 27506, United States
| | - Rahul V Haware
- Division of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University , Buies Creek, North Carolina 27506, United States
| | - Lewis L Stevens
- Division of Pharmaceutics and Translational Therapeutics, College of Pharmacy, The University of Iowa , Iowa City, Iowa 52242, United States
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Adhikari K, Flurchick KM, Valenzano L. Volumetric influence on the mechanical behavior of organic solids: The case of aspirin and paracetamol addressed via dispersion corrected DFT. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.04.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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7
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A hybrid density functional study on the effects of pressure on paracetamol and aspirin polymorphs. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Effects of volumetric expansion in molecular crystals: A quantum mechanical investigation on aspirin and paracetamol most stable polymorphs. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2014.12.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
INTRODUCTION Cocrystallization is an effective crystal engineering approach for modifying the crystal structure and properties of drugs. The number of examples of solving drug formulation and manufacture problems by cocrystallization is rapidly growing. An updated review that systematically examines the cocrystal research in the context of drug delivery is timely and valuable. AREAS COVERED Topics covered in this review include nature of cocrystal, impact of cocrystallization on key pharmaceutical properties (both enhancement and deterioration), cocrystal preparation method and future directions in this field. The focus of this review is on the crystal engineering and pharmaceutical literature in the last 5 years. However, classical literature is also examined when relevant. EXPERT OPINION The most effective cocrystal research relies on both in-depth understanding of structure-property relationship and efficient preparation of desired cocrystals. The future cocrystal research will see growth in the areas of designing ternary and higher-order structures, cocrystals between neutral and ionic species, cocrystal polymorphism, cocrystal glasses and thermodynamics of cocrystallization.
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Affiliation(s)
- Changquan Calvin Sun
- University of Minnesota, College of Pharmacy, Department of Pharmaceutics, 9-127B Weaver-Densford Hall, 308 Harvard Street S.E., Minneapolis, MN 55455, USA.
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Hamad ML, Bowman K, Smith N, Sheng X, Morris KR. Multi-scale pharmaceutical process understanding: From particle to powder to dosage form. Chem Eng Sci 2010. [DOI: 10.1016/j.ces.2010.01.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Klevan I, Nordström J, Bauer-Brandl A, Alderborn G. On the physical interpretation of the initial bending of a Shapiro–Konopicky–Heckel compression profile. Eur J Pharm Biopharm 2009; 71:395-401. [DOI: 10.1016/j.ejpb.2008.09.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 08/13/2008] [Accepted: 09/30/2008] [Indexed: 10/21/2022]
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12
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Duncan-Hewitt WC. Uniaxial Compaction Modelled using the Properties of Single Crystals. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049309047190] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lee J. Structural heterogeneity of pharmaceutical compacts probed by micro-indentation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:1981-1990. [PMID: 17943416 DOI: 10.1007/s10856-007-3283-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 09/18/2007] [Indexed: 05/25/2023]
Abstract
Indentation has been used for several decades to conveniently assess the hardness and modulus of various compacts. However, this measurement is dependent on the size of the indentation area from a few nanometers to several millimeters, which is determined by the maximum indentation force (MIF). Micro-indentation often loses its ability to give an accurate representation of the hardness due to its relatively small micron-size indentation area compared with the dimensions of the structural inhomogeneity of compacts. This study used a different approach to micro-indentation by examining whether this method can probe the inhomogeneity of compacts with varying MIF. Two typical pharmaceutical excipients, one brittle and one ductile, were used as model compacts. The representative hardness and modulus values were available when the MIF was >1000 mN. Changes in the standard deviation of the indentation hardness reflected the structural inhomogeneity of the compacts, which was found to increase with decreasing MIF to below 800 mN in the case of the microcrystalline cellulose compacts. The information on the structural inhomogeneity obtained by micro-indentation appears to be consistent with the observations from microscopy investigations. Anisotropy and other related structural information could be readily obtained by probing the two different surfaces of compacts with changing MIF, one parallel and the other perpendicular to the compaction pressure direction.
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Affiliation(s)
- Jonghwi Lee
- Department of Chemical Engineering and Materials Science, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul, 156-756, South Korea.
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Mohapatra H, Eckhardt CJ. Elastic Constants and Related Mechanical Properties of the Monoclinic Polymorph of the Carbamazepine Molecular Crystal. J Phys Chem B 2008; 112:2293-8. [DOI: 10.1021/jp077014c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Himansu Mohapatra
- Department of Chemistry, Center for Materials Research and Analysis, University of NebraskaLincoln, Lincoln, Nebraska 68588-0304
| | - Craig J. Eckhardt
- Department of Chemistry, Center for Materials Research and Analysis, University of NebraskaLincoln, Lincoln, Nebraska 68588-0304
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Liao X, Wiedmann TS. Measurement of Process-Dependent Material Properties of Pharmaceutical Solids by Nanoindentation. J Pharm Sci 2005; 94:79-92. [PMID: 15761932 DOI: 10.1002/jps.20227] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of this work was to evaluate nanoindentation as a means to characterize the material properties of pharmaceutical solids. X-ray diffraction of potassium chloride and acetaminophen showed that samples prepared by cooling a melt to a crystalline sample as opposed to slow recrystallization had the same crystal structure. With analysis of the force-displacement curves, the KCl quenched samples had a hardness that was 10 times higher than the recrystallized KCl, while acetaminophen quenched samples were 25% harder than the recrystallized samples. The elastic moduli of the quenched samples were also much greater than that observed for the recrystallized samples. Although the elasticity was independent of load, the hardness increased with load for acetaminophen. With each sample, the flow at constant load increased with applied load. Etching patterns obtained by atomic force microscopy showed that the KCl quenched sample had a higher dislocation density than the recrystallized sample, although there was no evident difference in the acetaminophen samples. Overall, the differences in the observed sample properties may be related to the dislocation density. Thus, nanoindentation has been shown to be a sensitive method for determining a processed-induced change in the hardness, creep, and elasticity of KCl and acetaminophen.
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Affiliation(s)
- Xiangmin Liao
- University of Minnesota, Department of Pharmaceutics, 308 Harvard St. SE, Minneapolis, Minnesota 55455, USA
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Liao X, Wiedmann TS. Characterization of pharmaceutical solids by scanning probe microscopy. J Pharm Sci 2004; 93:2250-8. [PMID: 15295786 DOI: 10.1002/jps.20139] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The force-displacement profiles of four well-characterized materials that represent both soft/hard and plastic/brittle materials have been obtained using a novel nanoindentation technique. Flat surfaces of acetaminophen, potassium chloride, sucrose, and sodium stearate were prepared by melting or recrystallization, and the melting points were measured. Topographic and the corresponding first derivative images were obtained both before and after indentation. The materials were indented using a 10 s loading time, followed by a 2 s hold, and ending with a 10 s unloading time thereby providing a unique force-displacement profile for each material. The loading profile of acetaminophen was discontinuous, whereas the profiles for the other three materials were smooth. The profiles were analyzed and the rank order of hardness was sucrose > acetaminophen > KCl > sodium stearate, which is consistent with the literature. The rank order of the stiffness, which is related to the modulus of elasticity, was sucrose > KCl > acetaminophen > sodium stearate. Given the flexibility and power of this approach, nanoindentation coupled with atomic force microscopy may be a useful means to characterize materials for evaluating tablet-processing conditions, perhaps at a preformulation stage.
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Affiliation(s)
- Xiangmin Liao
- University of Minnesota, Department of Pharmaceutics, 308 Harvard St. SE, Minneapolis, Minnesota 55455, USA
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Bandyopadhya R, Grant DJW. Plasticity and slip system of plate-shaped crystals of L-lysine monohydrochloride dihydrate. Pharm Res 2002; 19:491-6. [PMID: 12033385 DOI: 10.1023/a:1015151830473] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To identify the slip system of L-lysine monohydrochloride dihydrate (LH) and to relate it to the deformation behavior under uniaxial compression. METHODS The indentation hardness of the [100] face and the indentation moduli of the [100] and [011] faces of plate-shaped single crystals of LH (LHP) were determined using Knoop and Berkovich indenters, respectively. The deformation behavior during uniaxial compression was studied by the punch-stress vs. punch-displacement profile and by electron microscopy of the deformed crystals within cracked compacts. RESULTS The different indentation (elastic) moduli of the [100] and [011] faces of the crystals are consistent with the molecular packing density along these planes and suggest anisotropy. The existence of the [001] <100> slip system is proposed based on the pattern of changing indentation hardness with varying orientation of the Knoop indenter. A jagged uniaxial compression profile suggests deformation by mechanical twinning and not simple slip. The hypothesis of deformation by mechanical twinning is supported by the appearance of twin bands along the crystal faces as observed by electron microscopy of the cracked compacts. CONCLUSIONS During compression, most LHP crystals have their [100] faces oriented normal to, or inclined to, the compression axis, thereby facilitating plastic deformation along the [001] <100> slip system by mechanical twinning. Due to the low attachment energy between them, the [001] planes can also act as cleavage planes. This study demonstrates that knowledge of the crystal structure and slip systems can be used to model the tableting and compaction behavior of molecular crystals, such as LH.
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Affiliation(s)
- Rebanta Bandyopadhya
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis 55455-0343, USA
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Roberts RJ, Rowe RC. Brittle-ductile transitions in sucrose and the influence of lateral stresses during compaction. J Pharm Pharmacol 2000; 52:147-50. [PMID: 10714943 DOI: 10.1211/0022357001773788] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Sucrose, in a range of particle sizes, has been compacted to investigate both the effect of brittle-ductile transition and the effect of lateral stresses on the deformation stress as measured using Heckel plots. All particles with a diameter greater than 30 microm exhibited cracking in line with both theoretical predictions and literature data from hammer and ball milling. In addition, crack lengths in compressed particles examined microscopically were very similar to those predicted from the deformation stress, confirming the applicability of the model.
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Affiliation(s)
- R J Roberts
- Zeneca Pharmaceuticals, Macclesfield, Cheshire, UK
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Roberts RJ, Payne RS, Rowe RC. Mechanical property predictions for polymorphs of sulphathiazole and carbamazepine. Eur J Pharm Sci 2000; 9:277-83. [PMID: 10594385 DOI: 10.1016/s0928-0987(99)00065-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The mechanical properties of polymorphs of sulphathiazole and carbamazepine have been determined experimentally by three-point beam bending. It is shown that the mechanical properties of sulphathiazole and carbamazepine polymorphs can be predicted using the atom-atom potential model applied to lattice dynamics, as long as account is taken of crystal morphology when considering the experimental results.
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Affiliation(s)
- R J Roberts
- ZENECA Pharmaceuticals, Silk Road Business Park, Charter Way, Macclesfield, Cheshire, UK.
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Duncan-Hewitt W. Modeling the Compression Behavior of ParticleAssemblies from the Mechanical Properties of Individual Particles. DRUGS AND THE PHARMACEUTICAL SCIENCES 1995. [DOI: 10.1201/b14207-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Podczeck F, Newton J, James M. Adhesion and friction between powders and polymer or aluminium surfaces determined by a centrifuge technique. POWDER TECHNOL 1995. [DOI: 10.1016/0032-5910(94)02955-n] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Duncan-Hewitt WC, Papadimitropoulos EA. Deformation kinetics of potassium bromide crystals predict tablet stress relaxation. J Pharm Sci 1994; 83:91-5. [PMID: 8138918 DOI: 10.1002/jps.2600830121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A model relating the interparticulate contact stress within a tablet matrix with the compaction stress was developed previously to permit the nonlinear deformation kinetic analysis of the viscoelastic behavior of pharmaceutical tablets with the known properties of the tablet constituents. The present research was undertaken to determine whether the inverse operation (i.e., using tablet stress relaxation to determine single crystal properties) was possible. The stress relaxation of potassium bromide (KBr) compacts was evaluated as a function of temperature and relative density, and an attempt was made to calculate the deformation kinetic parameters. The stress relaxation of KBr did not fit the model under ambient conditions for two reasons: (1) KBr has two slip systems with approximately the same shear stress at room temperature; and (2) KBr strain-hardens. When these complications were taken into consideration, the stress relaxation behavior could be explained. Therefore, whereas single crystal tests are capable of yielding parameters that can be used to predict compact behavior, the inverse process of quantifying fundamental material parameters from compact behavior is problematic due to the difficulty of determining, a priori, all the processes that operate simultaneously.
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