Related Experiment Video
Updated: Jul 9, 2026

Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization
Published on: December 25, 2017
Molecular and thermodynamic aspects of solubility advantage from solid dispersions
Shyam Sunder Bansal1, Aditya Mohan Kaushal, Arvind Kumar Bansal
1Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Punjab 160 062, India. akbansal@niper.ac.in
Abstract:
The solubility behavior of solid dispersions of two drugs with similar structures was studied. Valdecoxib (VLB) and etoricoxib (ETB) were used as model drugs, and their solid dispersions were prepared with 1, 2, 5, 10, 15, and 20% w/w poly(vinylpyrrolidone) (PVP) by the quench cooling method. The interactions between the drug and polymer molecules were studied by Fourier transform infrared spectroscopy (FT-IR). The thermodynamic aspects of solubility behavior were studied by plotting van't Hoff plots. Both the drugs showed significant differences in their solubility behavior. In the case of VLB, solubility was found to increase significantly with increasing PVP concentration. ETB however did not show any significant solubility enhancement and was found to have decreased solubility at high PVP concentrations. H-bonding interactions were established between VLB and PVP molecules, while none were observed in ETB-PVP dispersions. Solution thermodynamics of amorphous and crystalline forms of both the drugs were studied by van't Hoff plots. The results obtained showed very high negative value of Gibbs free energy for VLB as compared to ETB, thus demonstrating high spontaneity of VLB solubilization. Entropy of amorphous VLB was found to be highly favorable, while being slightly unfavorable for ETB. From this study H-bonding interactions were found to play a major role in dictating the solubility behavior of these drugs from solid dispersions.
More Related Videos
05:08Solubility of Hydrophobic Compounds in Aqueous Solution Using Combinations of Self-assembling Peptide and Amino Acid
Published on: September 20, 2017
13:05Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments
Published on: January 23, 2018
Related Concept Videos
Solution Formation
This selective solubility...
Solubility
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
Chemical and Solubility Equilibria
Solubility Equilibria: Overview
Solubility is important in biological and environmental processes. A notable...
Liquid–Solid Solutions
Bioavailability Enhancement: Drug Solubility Enhancement