Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Ionic Strength: Effects on Chemical Equilibria01:19

Ionic Strength: Effects on Chemical Equilibria

2.1K
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary...
2.1K
Complexation Equilibria: Factors Influencing Stability of Complexes01:09

Complexation Equilibria: Factors Influencing Stability of Complexes

626
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
626
Complexation Equilibria: The Chelate Effect01:19

Complexation Equilibria: The Chelate Effect

864
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
864
Formation of Complex Ions03:45

Formation of Complex Ions

24.9K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
24.9K
Buffer Effectiveness02:19

Buffer Effectiveness

52.7K
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
52.7K
EDTA: Conditional Formation Constant01:09

EDTA: Conditional Formation Constant

1.6K
Each EDTA molecule has six binding sites: four carboxyl groups and two amino groups. The fully protonated form of EDTA is represented as H6Y2+. However, it can exist in different forms, H5Y+, H4Y, H3Y−, H2Y2−, and HY3−, depending on the pH of the solution. In very basic solutions with pH > 10.17, the fully deprotonated form, Y4−, is the predominant species that readily complexes with metal ions in a 1:1 ratio.
For the equilibrium reaction of the metal with the...
1.6K

You might also read

Related Articles

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

Sort by
Same author

Establishing experimental parameters for biphasic transfer in vitro lipolysis model.

International journal of pharmaceutics·2026
Same author

Preformulation studies of levonorgestrel: A supplier variation analysis.

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

Development of high-concentration long-acting injectable formulations of TBAJ-587 and TBAJ-876 as an extended treatment strategy against tuberculosis.

Journal of controlled release : official journal of the Controlled Release Society·2026
Same author

Impact of solvent choice during microfluidic manufacture on the in vivo performance of liposomal doxorubicin.

Drug delivery and translational research·2026
Same author

In Vitro Evaluation of Poly(D,L-lactide-co-glycolide) In Situ Gels and Pharmacokinetics Following Subcutaneous Injection in Rats for Model Drugs.

Pharmaceutics·2026
Same author

Accelerating Generic Long-Acting Antiretrovirals for Global HIV Treatment: Workshop Findings and a Roadmap to Access.

Clinical pharmacology and therapeutics·2026

Related Experiment Video

Updated: Nov 16, 2025

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

19.1K

Specific Buffers Affect the Stability of a Charged Cyclodextrin Complex Via Competitive Binding and Ionic Strength.

Lisa Samuelsen1, René Holm2, Christian Schönbeck1

  • 1Department of Science and Environment, Roskilde University, Roskilde, Denmark.

Journal of Pharmaceutical Sciences
|February 19, 2021
PubMed
Summary

Ionic strength and buffer choice significantly impact the stability of sulfobutylether-β-cyclodextrin complexes with bile salts. Carboxylic acid buffers, in particular, reduce complex stability through competitive binding mechanisms.

Keywords:
ComplexationCyclodextrin(s)EquilibriaFormulationIsothermal titration calorimetry (ITC)

More Related Videos

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids
10:32

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

Published on: March 2, 2012

24.8K
Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
09:49

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability

Published on: April 2, 2015

10.8K

Related Experiment Videos

Last Updated: Nov 16, 2025

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

19.1K
On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids
10:32

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

Published on: March 2, 2012

24.8K
Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
09:49

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability

Published on: April 2, 2015

10.8K

Area of Science:

  • Supramolecular Chemistry
  • Physical Chemistry

Background:

  • Bile salt-cyclodextrin complexation is crucial in pharmaceutical formulations.
  • Ionic strength and buffer composition are known to influence binding equilibria.

Purpose of the Study:

  • To investigate the effects of ionic strength and various buffers on the binding stability between taurochenodeoxycholate and sulfobutylether-β-cyclodextrin.
  • To elucidate the mechanisms by which buffers and ionic strength modulate complex stability.

Main Methods:

  • Spectrophotometric titration was employed to determine binding constants.
  • Systematic variation of ionic strength and buffer species (11 types) was performed.

Main Results:

  • The stability constant of the sulfobutylether-β-cyclodextrin complex increased with ionic strength, ranging from 34,400 M⁻¹ to 114,000 M⁻¹ at 0.15 M.
  • Carboxylic acid buffers (citric, succinic) significantly reduced the stability constant, indicating competitive binding.
  • Three distinct buffer groupings emerged when accounting for ionic strength variations, with carboxylic acids showing a distinct effect.

Conclusions:

  • Both buffer type and ionic strength are critical factors influencing the stability of ionic cyclodextrin complexes.
  • Understanding these effects is essential for accurate characterization and application of cyclodextrin-based systems.
  • Competitive binding by certain buffers can significantly alter observed stability constants.