Crystalline Forms
Crystalline Forms - Related Videos
01:21
Polymer Classification: Crystallinity
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2023
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains. Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
11:17
Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
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Cited by 107 •
2016
A novel methodology is presented to synthesize and program main-chain liquid-crystalline elastomers using commercially available starting monomers. A wide range of thermomechanical properties was tailored by adjusting the amount of crosslinker, while the actuation performance was dependent on the amount of applied strain during programming.
12:04
Microfluidic Preparation of Liquid Crystalline Elastomer Actuators
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Cited by 3 •
2018
This article describes the microfluidic process and parameters to prepare actuating particles from liquid crystalline elastomers. This process allows the preparation of actuating particles and the variation of their size and shape (from oblate to strongly prolate, core-shell, and Janus morphologies) as well as the magnitude of actuation.
05:26
Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks
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Cited by 2 •
2023
Here, we demonstrate a protocol for the two-step synthesis of single-crystalline core-shells using a non-isostructural metal-organic framework (MOF) pair, HKUST-1 and MOF-5, which have well-matched crystal lattices.
08:17
Free-form Light Actuators — Fabrication and Control of Actuation in Microscopic Scale
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2016
Here, we fabricate 3D polymeric micro/nano structures in which both the shape and the molecular alignment can be engineered with nanometer scale accuracy by the use of direct laser writing. Light induced deformation of several types of liquid crystalline elastomer microstructures can be controlled in the microscopic scale.
FAQs
Different lattice arrangements can produce distinct solubility, dissolution rate, stability, and mechanical properties even when the chemical substance remains the same. These differences affect how readily a formulation dissolves, how well it withstands manufacturing and storage, and how consistently it performs as a dosage form. Comparing forms therefore helps developers select an arrangement suited to the intended clinical use.
These categories represent different solid-state possibilities for a chemical substance and may not behave equivalently during formulation or storage. Their distinct arrangements can influence physical properties linked to dosage performance, including stability, dissolution, and bioavailability. Treating each form as interchangeable without characterization could create variability in product quality or clinical performance, so form-specific assessment is important.
Changes in solvent, temperature, pressure, or crystallization rate can favor different ordered arrangements. These variables affect how molecules organize as a solid forms, which may determine the properties of the resulting material. Controlling them during development helps reduce unintended form changes and supports reproducible production of the crystalline form selected for a pharmaceutical product.
A selected form can differ in solubility and dissolution rate, which may influence how much of a substance becomes available for use by the body. Because these properties can affect bioavailability, form selection is relevant to clinical formulation rather than only to materials characterization. Developers evaluate the relationship between solid-state properties and dosage performance before establishing a preferred form.
Development begins by considering possible forms and the conditions that may produce them, followed by solid-state characterization to distinguish and compare the resulting materials. Researchers then assess properties such as solubility, dissolution rate, stability, and mechanical behavior. The findings support selection of a preferred form and help define controls for manufacturing, storage, and dosage consistency.
Manufacturing controls help ensure that the intended solid-state form remains consistent from one production process or batch to another. This consistency supports predictable physical properties, accurate dosage performance, and product stability. Without control, changes in crystallization conditions could produce a different form with altered behavior, creating quality concerns even though the underlying chemical substance is unchanged.
Solid-state characterization connects the identity of a crystalline form with properties that matter for clinical products, including dissolution, stability, mechanical performance, and bioavailability. It provides evidence for choosing a formulation form and for assessing whether manufacturing and storage preserve that choice. In this way, characterization supports both formulation development and ongoing product quality evaluation.