Related Experiment Video
Updated: Jun 26, 2026
10:10
Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Physicochemical characterization of efavirenz-cyclodextrin inclusion complexes
Sateeshkumar Sathigari1, Gurkishan Chadha, Y-H Phillip Lee
1Department of Pharmacal Sciences, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA.
AAPS Pharmscitech
|January 17, 2009
Summary
Efavirenz (EFV) solubility and dissolution were improved by forming inclusion complexes with cyclodextrins (CDs). Hydroxypropyl beta-CD (HPbetaCD) and randomly methylated beta-CD (RMbetaCD) showed the most significant enhancement, potentially improving drug absorption.
Area of Science:
- Pharmaceutical Sciences
- Drug Delivery Systems
- Physical Chemistry
Background:
- Efavirenz (EFV), an antiretroviral drug, exhibits poor aqueous solubility, limiting its oral absorption due to slow dissolution rates.
- Improving the dissolution rate of poorly soluble drugs like EFV is crucial for enhancing their bioavailability.
Purpose of the Study:
- To characterize the inclusion complexes of EFV with beta-cyclodextrin (beta-CD), hydroxypropyl beta-CD (HPbetaCD), and randomly methylated beta-CD (RMbetaCD).
- To evaluate the potential of these inclusion complexes to enhance the solubility and dissolution of EFV.
Main Methods:
- Phase solubility studies were conducted to characterize liquid-state complexation.
- Solid-state characterization utilized X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy.
- Dissolution studies were performed using USP dissolution apparatus in distilled water.
Main Results:
- Phase solubility diagrams indicated different interaction types with various CDs.
- Stability constants (K(s)) for EFV-CD complexes ranged from 288 M(-1) for beta-CD to 1,073 M(-1) for RMbetaCD.
- Freeze-dried inclusion complexes with HPbetaCD and RMbetaCD demonstrated substantially higher EFV dissolution rates.
Conclusions:
- Complexation with HPbetaCD and RMbetaCD significantly enhances EFV solubility and dissolution.
- These cyclodextrin complexes offer a promising strategy to overcome the dissolution rate-limited absorption of Efavirenz.
Related Concept Videos
01:28Factors Influencing Drug Absorption: Pharmaceutical Parameters
Solid dosage forms such as tablets and capsules undergo rigorous manufacturing processes to ensure stability and effectiveness. Their dissolution and absorption properties are influenced significantly by the choice of excipients (inactive ingredients that serve various roles in the formulation), and the methodology applied during production. The manufacturing parameters, such as compression force and granulation techniques, significantly affect dissolution rates. Elevated compression forces...
01:22Factors Influencing Drug Absorption: Physicochemical Parameters
The physicochemical characteristics of drugs play a crucial role in formulating stable and bioavailable drug products. The solubility of a drug, governed by the varying pH along the GI tract and its dissociation constant (pKa), is pivotal in determining its ionization state and absorption rate. Notably, weak acids and bases remain unionized and are absorbed more rapidly.
Enhanced drug absorption can be achieved by reducing particle sizes and increasing surface areas, thereby facilitating...
Enhanced drug absorption can be achieved by reducing particle sizes and increasing surface areas, thereby facilitating...
01:05Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Improving a drug's stability in the gastrointestinal (GI) tract is paramount for enhancing its bioavailability and therapeutic effectiveness. Various strategies are employed to protect the drug from the harsh gastric milieu and to ensure its release and absorption at the desired site within the GI tract.Polymer coatings are one such method used to shield drugs from the stomach's acidic environment. By preventing premature drug release, these coatings improve the bioavailability of unstable...
01:20Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Orally administered drugs primarily enter the systemic circulation via passive diffusion through the intestinal membranes. The drug's absorption is influenced by drug stability in the gastrointestinal GI tract, membrane permeability, the surface area available for absorption, luminal drug concentration, and residence time in the lumen. Drug permeability can be enhanced by adjusting the lipophilicity, polarity, or molecular size of the drug, promoting its passive transport across intestinal...
01:30Modified-Release Drug Delivery Systems: Bioavailability
Modified-release (MR) dosage forms are designed to extend drug release over time, thereby maintaining stable plasma concentrations and reducing dosing frequency. However, their bioavailability is typically below 100% due to incomplete drug release and presystemic metabolism, and limitations in drug permeability across the gastrointestinal epithelium, all of which can restrict the fraction of the drug reaching systemic circulation. Consequently, studying the in vivo bioavailability of MR...
01:22Modified-Release Drug Delivery Systems: Drug Release Characteristics
Drug release from modified-release dosage forms is designed to achieve specific therapeutic effects by controlling the rate and extent of drug release. The classification of these drug release systems is based on key pharmacokinetic assumptions: drug disposition follows first-order kinetics, drug release is the rate-limiting step in absorption, and the released drug is rapidly and completely absorbed.There are four major models of drug release patterns. The first model is the slow zero-order...