[A study on inclusion complexes of cyclodextrin with three anticancer xanthines by fluorescence]

Area of Science:

• Pharmaceutical Chemistry
• Supramolecular Chemistry
• Analytical Chemistry

Background:

• Cyclodextrins (CDs) are widely used to improve drug solubility and bioavailability.
• 6-Mercaptopurine (6-MP), Azathioprine (BAN), and 8-Azaguanine (Azan) are anticancer drugs with potential formulation challenges.
• Understanding the formation and properties of their inclusion complexes is crucial for drug delivery.

Purpose of the Study:

• To investigate the formation of inclusion complexes between beta-Cyclodextrin (beta-CD) and HP-beta-Cyclodextrin (HP-beta-CD) with 6-MP, BAN, and Azan.
• To determine the influence of formation time and pH on the stability and characteristics of these inclusion complexes.
• To quantify the formation constants and stoichiometry of the developed inclusion complexes.

Main Methods:

• Fluorescence spectroscopy was employed to study the inclusion complexation.
• Systematic variation of formation time and pH to optimize complex formation.
• Determination of formation constants and stoichiometry through fluorescence data analysis.

Main Results:

• Inclusion complex formation was significantly influenced by formation time and pH, with optimal pH ranging from 7.7 to 12.
• HP-beta-CD exhibited faster complex formation compared to beta-CD.
• Fluorescence intensity increased with increasing cyclodextrin concentration, indicating successful complexation.
• All investigated inclusion complexes demonstrated a 1:1 stoichiometry.

Conclusions:

• Beta-cyclodextrin and HP-beta-cyclodextrin effectively form 1:1 inclusion complexes with 6-MP, BAN, and Azan.
• Formation time and pH are critical parameters for optimizing the formation and stability of these drug-cyclodextrin complexes.
• Fluorescence spectroscopy provides a reliable method for characterizing these inclusion complexes and determining their formation constants.