Assessment of Defects and Amorphous Structure Produced in Raffinose Pentahydrate upon Dehydration

Bates, Simon; Kelly, Ron C.; Ivanisevic, Igor; Schields, Paul J.; Zografi, George; Newman, Ann

doi:10.1002/jps.20944

Cited by 58 publications

(55 citation statements)

References 37 publications

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“…Although the PDF has historically been used on inorganic materials, it has recently received some attention from the pharmaceutical community and has been applied to molecular materials in crystalline and amorphous phases. There are examples in the literature of PDFs of molecular materials obtained from x-ray diffraction data from standard, widely available copper anode laboratory-based XRD instruments (7)(8)(9)(10), and also PDFs obtained from powder data collected on a high energy synchrotron source (2).…”

Section: Introductionmentioning

confidence: 99%

Data Requirements for the Reliable Use of Atomic Pair Distribution Functions in Amorphous Pharmaceutical Fingerprinting

et al. 2011

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Section: Introductionmentioning

confidence: 99%

Data Requirements for the Reliable Use of Atomic Pair Distribution Functions in Amorphous Pharmaceutical Fingerprinting

et al. 2011

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“…17,18 Since the degree of crystallinity is irrelevant to the method, PDF may be applied to glasses as well as to perfect crystals and any state in between. It thus is a method to extract more detailed information from X-ray powder diffraction results that would usually lead to simply designating the product as ''poorly crystalline'' or ''amorphous.…”

Section: Introductionmentioning

confidence: 99%

Pair distribution function X‐ray analysis explains dissolution characteristics of felodipine melt extrusion products

Nollenberger

Gryczke

Meier

et al. 2009

Journal of Pharmaceutical Sciences

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“…In the material science community the PDF technique has been used for several decades (101-105) and has more recently been applied by the pharmaceutical community to study short-and long-range order amorphous glassy materials (106)(107)(108)(109)(110)(111). It has been used in studies to investigate crystalline defects, help in the crystal structure determination (106,107,110), characterization of polymer/drug systems (111)(112)(113) and the use of multivariate data analysis has alleviated the interpretation of PDF (108,111). It could be a possible route to gain a deeper insight into the degree of disorder in a milled sample.…”

Section: Atomic Pairwise Distributionmentioning

confidence: 99%

Methods of amorphization and investigation of the amorphous state

Einfalt¹,

Planinšek²,

Hrovat³

2013

Acta Pharmaceutica

117

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.g., polymorphs) provides pharmaceutical scientists with an opportunity to select the preferred form of the material to be used in a formulation. This is very useful since critical properties, such as particle morphology and dissolution properties, are frequently different in the different physical forms of a material. The amorphous form of pharmacologically active materials has received considerable attention because, in theory, it represents the most energetic solid state of a material, and should thus provide the biggest advantages in terms of dissolution rate and bioavailability (1). However, the amorphous form also shows various disadvantages, such as lower physical stability compared to crystals.The structure of an amorphous solid is usually described as possessing a crystal--like short-range molecular arrangement, but lacking a long-range order. As illustrated by Fig. 1, the immediate environment of a molecule (m) in an amorphous solid may not differ significantly from that in a crystal (e.g., similar number of and distance to nearest neighbors), but an amorphous solid lacks any long-range transational-orientational symmetry that characterizes a crystal (1). However, this is only true when we are dealing The amorphous form of pharmaceutical materials represents the most energetic solid state of a material. It provides advantages in terms of dissolution rate and bioavailability. This review presents the methods of solid--state amorphization described in literature (supercooling of liquids, milling, lyophilization, spray drying, dehydration of crystalline hydrates), with the emphasis on milling. Furthermore, we describe how amorphous state of pharmaceuticals differ depending on the method of preparation and how these differences can be screened by a variety of spectroscopic (X-ray powder diffraction, solid state nuclear magnetic resonance, atomic pairwise distribution, infrared spectroscopy, terahertz spectroscopy) and calorimetry methods.

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Assessment of Defects and Amorphous Structure Produced in Raffinose Pentahydrate upon Dehydration

Cited by 58 publications

References 37 publications

Data Requirements for the Reliable Use of Atomic Pair Distribution Functions in Amorphous Pharmaceutical Fingerprinting

Data Requirements for the Reliable Use of Atomic Pair Distribution Functions in Amorphous Pharmaceutical Fingerprinting

Pair distribution function X‐ray analysis explains dissolution characteristics of felodipine melt extrusion products

Methods of amorphization and investigation of the amorphous state

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