Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

UV–Vis Spectroscopy of Conjugated Systems

UV–Vis Spectroscopy of Conjugated Systems

Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π&VeryThinSpace;→&VeryThinSpace;π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in the...

UV–Vis Spectroscopy: Molecular Electronic Transitions

UV–Vis Spectroscopy: Molecular Electronic Transitions

In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...

UV–Vis Spectroscopy: Woodward–Fieser Rules

UV–Vis Spectroscopy: Woodward–Fieser Rules

UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π&VeryThinSpace;→&VeryThinSpace;π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...

Spectroscopy of Carboxylic Acid Derivatives

Spectroscopy of Carboxylic Acid Derivatives

Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and unsymmetrical carbonyl vibration.
In the...

Valence Bond Theory

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...

Molecular Spectroscopy: Absorption and Emission

Molecular Spectroscopy: Absorption and Emission

Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Does magnesium permeate the skin? An ex vivo investigation of magnesium ion delivery through intact and barrier-disrupted skin.

European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V·2026

Same author

Special Issue on the 10th BBBB Conference on Pharmaceutical Sciences.

European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences·2026

Same author

Scalable microfluidic fabrication of optimized phospholipid nanocarriers for enhanced topical bioavailability: Analytical QbD integration and <i>ex vivo</i> skin permeation assessment.

International journal of pharmaceutics: X·2026

Same author

Water-Soluble Ammonium BODIPYs: Synthesis, Photophysics, Photogelation, and Antimicrobial Activity.

Chemistry, an Asian journal·2026

Same author

Symbolically Regressing Fish Biomass Spectral Data: A Linear Genetic Programming Method With Tunable Primitives.

Journal of the Royal Society of New Zealand·2026

Same author

Enhanced encapsulation and membrane retention of <i>Teleogryllus mitratus</i> protein via hydrophobic ion-pairing in nanostructured lipid carriers.

International journal of pharmaceutics: X·2026

Search research articles

Related Experiment Video

Updated: Jul 4, 2026

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients

Published on: August 9, 2022

Understanding the solid-state forms of fenofibrate--a spectroscopic and computational study.

Andrea Heinz¹, Keith C Gordon, Cushla M McGoverin

¹School of Pharmacy, University of Otago, Dunedin, New Zealand. andrea.heinz@stonebow.otago.ac.nz

European Journal of Pharmaceutics and Biopharmaceutics : Official Journal of Arbeitsgemeinschaft Fur Pharmazeutische Verfahrenstechnik E.V

|July 2, 2008

Summary

This study investigated fenofibrate

More Related Videos

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Published on: August 13, 2019

Advancements in the Metabolic Profiling of Three-Dimensional Brain Tumor Spheroids for Drug Screening

Advancements in the Metabolic Profiling of Three-Dimensional Brain Tumor Spheroids for Drug Screening

Published on: September 5, 2025

Related Experiment Videos

Last Updated: Jul 4, 2026

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients

Published on: August 9, 2022

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Published on: August 13, 2019

Advancements in the Metabolic Profiling of Three-Dimensional Brain Tumor Spheroids for Drug Screening

Advancements in the Metabolic Profiling of Three-Dimensional Brain Tumor Spheroids for Drug Screening

Published on: September 5, 2025

Area of Science:

Solid-state chemistry
Pharmaceutical sciences
Computational chemistry

Background:

Fenofibrate lacks strong intermolecular interactions like hydrogen bonding.
Understanding solid-state forms is crucial for drug efficacy and stability.

Purpose of the Study:

To investigate the structure of different solid-state forms of fenofibrate.
To analyze conformational and structural differences between crystalline and amorphous fenofibrate.
To monitor solid-state changes during amorphous fenofibrate recrystallization.

Main Methods:

Infrared (IR) and Raman spectroscopy.
Density Functional Theory (DFT) calculations (B3LYP 6-31G(d)).
In situ Raman spectroscopy and multivariate analysis.

Main Results:

Conformational differences in benzyl ring orientation and structural variations in aliphatic parts were identified.
Spectroscopic analysis indicated more random molecular orientations in amorphous fenofibrate due to weak intermolecular interactions.
Multiple solid-state forms, including metastable crystalline form II, were revealed and structurally analyzed.

Conclusions:

Vibrational spectroscopy, multivariate analysis, and quantum chemical modeling are effective for characterizing drug substances with subtle structural differences.
The study provides insights into the solid-state behavior of fenofibrate, crucial for pharmaceutical development.
Weak intermolecular interactions influence molecular arrangement in amorphous drug forms.