Formulation, Characterization, and In Vitro Drug Release Study of β-Cyclodextrin-Based Smart Hydrogels

Area of Science:

• Polymer Chemistry
• Materials Science
• Drug Delivery Systems

Background:

• Controlled drug delivery systems are crucial for improving therapeutic efficacy and patient compliance.
• pH-responsive hydrogels offer targeted drug release based on physiological pH variations.
• β-cyclodextrin-based polymers present unique properties for drug encapsulation and release.

Purpose of the Study:

• To fabricate novel pH-responsive polymeric hydrogels based on β-cyclodextrin-graft-poly(acrylic acid/itaconic acid).
• To investigate the potential of these hydrogels for the controlled delivery of theophylline.
• To characterize the physicochemical properties and drug release behavior of the fabricated hydrogels.

Main Methods:

• Free radical polymerization was employed to synthesize the hydrogels using β-cyclodextrin, acrylic acid, itaconic acid, and ethylene glycol dimethacrylate.
• Theophylline loading was achieved via absorption and diffusion.
• Hydrogel characterization included FTIR, TGA, XRD, SEM, and sol-gel analysis.
• Swelling and drug release studies were conducted at different pH values (1.2, 4.6, and 7.4).

Main Results:

• FTIR confirmed crosslinking and drug loading; TGA showed enhanced thermal stability compared to pure components.
• XRD indicated decreased crystallinity after crosslinking; SEM revealed a rough surface morphology.
• Sol-gel analysis demonstrated an increase in gel fraction with higher component concentrations.
• Dynamic swelling and theophylline release were significantly higher at pH 7.4 compared to pH 1.2, confirming pH-responsiveness.
• Increased β-cyclodextrin, acrylic acid, and itaconic acid enhanced swelling, drug release, loading, and porosity, while higher crosslinker concentration reduced these properties.

Conclusions:

• The synthesized β-cyclodextrin-graft-poly(acrylic acid/itaconic acid) hydrogels exhibit pH-responsive behavior and enhanced thermal stability.
• These hydrogels demonstrate significant potential as carriers for the controlled release of theophylline.
• The study highlights the tunable properties of these novel hydrogels for drug delivery applications.