Related Experiment Video
Updated: Jul 19, 2026

Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Study of the interaction between S(--) bupivacaine and 2-hydroxypropyl-beta-cyclodextrin
Carolina Morales Moraes1, Priscila Abrami, Eneida de Paula
1Faculty of Pharmacy, University of Sorocaba, Cidade Universitária, Rodovia Raposo Tavares, Km 92,5, 18023-000 Sorocaba, SP, Brazil.
This study characterizes a stable inclusion complex between the local anesthetic S(--) bupivacaine and 2-hydroxypropyl-beta-cyclodextrin. The complexation enhances drug solubility and provides thermodynamic data for potential pain treatment formulations.
Area of Science:
- Pharmaceutical Chemistry
- Drug Delivery Systems
- Analytical Chemistry
Background:
- Local anesthetics, like S(--) bupivacaine, are crucial for pain management.
- Enhancing drug solubility and stability is key for effective therapeutic formulations.
- Cyclodextrins, such as 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD), are widely used to improve drug properties.
Purpose of the Study:
- To characterize the inclusion complex formation between S(--) bupivacaine and HP-beta-CD.
- To determine the stoichiometry and apparent stability constants of the S(--) bupivacaine:HP-beta-CD complex.
- To investigate the influence of pH and temperature on complexation and drug solubility.
Main Methods:
- Reversed-phase high-performance liquid chromatography (HPLC) with HP-beta-CD as a mobile phase additive.
- Solubility isotherms studies at varying pH (7.4 and 10.5) and temperatures.
- Continuous variation method to determine complex stoichiometry.
Main Results:
- HPLC analysis confirmed complex formation, with decreased retention times correlating to increased HP-beta-CD concentration.
- Solubility of S(--) bupivacaine increased significantly in the presence of HP-beta-CD, especially at higher pH.
- Apparent stability constants (K) were determined (13.1±2.8 M⁻¹ at pH 7.4 and 95.4±11.8 M⁻¹ at pH 10.5), indicating a stable 1:1 complex.
Conclusions:
- A stable 1:1 inclusion complex of S(--) bupivacaine and HP-beta-CD is formed.
- HP-beta-CD effectively enhances the solubility of S(--) bupivacaine.
- The characterized complex holds potential for developing improved therapeutic formulations for pain management.
Related Concept Videos
Depolarizing Blockers: Pharmocokinetics
Hepatic Drug Excretion: Enterohepatic Cycling
Post-release drugs and metabolites can be reabsorbed into the body from the intestine. For conjugated metabolites like glucuronides, reabsorption requires enzymatic hydrolysis by intestinal microflora. This...
Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Two-Compartment Open Model: IV Bolus Administration
The disparity between drug input and the sum of drug transfer rates between...
Site-Targeted Drug Delivery Systems: Polymeric Carriers
One-Compartment Open Model for IV Bolus Administration: General Considerations
The drug's presence in the body is defined by an equation representing the difference between the rates of drug entry and exit. Key parameters—elimination rate constant, half-life,...

