Optical Crystallographic Characteristics of Some USP Drugs

Jordan, David D.

doi:10.1002/jps.2600821218

Cited by 11 publications

(5 citation statements)

References 1 publication

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“…The growth direction was established as <100> by powder X-ray diffraction. The intermediate refractive index, n β , as previously reported, 53 must correspond to the axis around which the crystal twists.…”

Section: ■ Helicoidal Crystalsmentioning

confidence: 56%

“…The growth direction was established as <100> by powder X-ray diffraction. The intermediate refractive index is also n β as previously reported and must likewise correspond to <100>. The twist sense of ( S )-naproxen crystals is left-handed determined by sensing-the-screw method, that is, by watching the bands of extinction move up or down with respect to a rotation about a radial axis.…”

Section: Twisting Crystals Over-the-countermentioning

confidence: 58%

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Polymorphism and Morphology Folklore

Kahr

Tan

et al. 2019

Crystal Growth & Design

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Polymorphism of molecular crystals was Joel Bernstein’s (1941–2019) scientific focus. Polymorphism also has been the subject of lore: (1) McCrone made popular the belief that the longer you study a substance the more polymorphs you are likely to find, and (2) Bernstein made popular so-called disappearing polymorphs, forms that no matter how long you look you can no longer find (in the absence of extraordinary measures). Here, we add the following lore: (3) Molecular crystals with helicoidal morphologies are as common as those that are polymorphic. The aforementioned observations of McCrone, Bernstein, and the present authors do not rise to the level of scientific principles. They are nevertheless guides grounded in laboratory experience. The experiences out of which the third statement emerges is the work of overlooked researchers, as well as a long list of substances with helicoidal morphologies assembled during the past decade in our laboratories. Here, the claim of the ubiquity of twisted crystals is supported with a particular demonstration with polymorphs of active pharmaceutical ingredients, favorites of Bernstein because of their intersection with the law. It was previously shown that crystallites of particular polymorphs of aspirin and acetaminophen (paracetamol) twist as they grow. No such observations have been made for the other two popular over-the-counter pain relief medicines, ibuprofen and naproxen. They are given here. Twisting among all four common pain medicine crystals seems improbable, to us, and supports a fact about molecular crystal morphology that is not widely appreciated but hiding in plain view.

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Section: ■ Helicoidal Crystalsmentioning

confidence: 56%

Section: Twisting Crystals Over-the-countermentioning

confidence: 58%

Polymorphism and Morphology Folklore

Kahr

Tan

et al. 2019

Crystal Growth & Design

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“…Polarized light microscopy (PLM) was initially used to observe the crystallization of the acetaminophen films dip-coated from ethanol solutions. Acetaminophen is optically active so crystallization was assessed by viewing the film surface through cross-polarizers on the microscope. , Extinction was observed in amorphous regions . This was verified later with FTIR microscopy.…”

Section: Resultsmentioning

confidence: 90%

“…Acetaminophen is optically active so crystallization was assessed by viewing the film surface through cross-polarizers on the microscope. 8,15 Extinction was observed in amorphous regions. 16 This was verified later with FTIR microscopy.…”

Section: Resultsmentioning

confidence: 98%

Transformation and Growth of Polymorphic Nuclei through Evaporative Deposition of Thin Films

Yeager

Ramos

Mack

et al. 2012

Crystal Growth & Design

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Rapidly dip-coating a silicon substrate in an acetaminophen solution creates a thin film of polymorphic nuclei, and the relative amounts of each polymorph vary with the type of solvent. Polarized light microscopy (PLM) revealed that all films were initially amorphous and gradually crystallized over time scales of minutes to hours. Fourier transform infrared spectroscopy (FTIR) was used to identify the polymorphic form during crystallization and weeks after apparent stabilization of growth. Crystallites that initially nucleated from the amorphous films were found to be the metastable orthorhombic form. Over time, the orthorhombic crystallites stopped growing and the remaining amorphous regions transformed to the stable monoclinic form. The choice of solvent determined how fast the orthorhombic crystallites grew and thus controlled the polymorphic character of the film. For example, dip-coating from an ethanol solution produced a largely orthorhombic film, while water yielded a film with mixed character. Kinetic arguments are made to discuss these results in terms of relative nucleation rates, supersaturation, and evaporation rate of the solvent. We demonstrate that PLM and FTIR are suitable tools for exploring phase space with these thin films. This methodology might be applied broadly to polymorph screening and selection in evaluating pharmaceutical materials.

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“…The formation process of MCC was observed under PLM which was useful for studying the optical property of crystals. PLM identified the formation of a new crystalline form through the alteration of the crystal habit ( 25 26 ). A phenomenon of a different crystal habit between DES and coformers could provide preliminary information about the probability of interaction between both components to produce a new crystal form.…”

Section: Discussionmentioning

confidence: 99%

Synthesis, characterization, and stability study of desloratadine multicomponent crystal formation

Ainurofiq¹,

Mauludin²,

Mudhakir³

et al. 2018

Res Pharma Sci

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This study describes the formation of multicomponent crystal (MCC) of desloratadine (DES). The objective of this study was to discover the new pharmaceutical MCC of DES using several coformers. The MCC synthesis was performed between DES and 26 coformers using an equimolar ratio with a solvent evaporation technique. The selection of the appropriate solvent was carried out using 12 solvents. The preview of the MCC of DES was performed using polarized light microscopy (PLM). The formation of MCC was confirmed using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The accelerated stability of MCC at 40 °C and relative humidity of 75% was investigated using PXRD and FTIR. Depending on the prior evaluation, DES and benzoic acid (BA) formed the MCC. PLM and SEM results showed that crystal habit of combination between DES and BA differed from the constituent components. Moreover, the diffractogram pattern of DES-BA was distinct from the constituent components. The DSC thermogram showed a new peak which was distinct from both constituent components. The FTIR study proved a new spectrum. All characterizations indicated that a new solid crystal was formed, ensuring the MCC formation. In addition, DES-BA MCC had both chemical and physical stabilities for a period of 4 months.

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Optical Crystallographic Characteristics of Some USP Drugs

Cited by 11 publications

References 1 publication

Polymorphism and Morphology Folklore

Polymorphism and Morphology Folklore

Transformation and Growth of Polymorphic Nuclei through Evaporative Deposition of Thin Films

Synthesis, characterization, and stability study of desloratadine multicomponent crystal formation

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