Textural Properties of Carbopol^® Gel with Curcumin and Curcumin-HPβCD Inclusion Complex and Biological Activities

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Biochemistry

Background:

• Curcumin, a natural compound, possesses significant antioxidant and antimicrobial properties but suffers from poor solubility and bioavailability.
• Cyclodextrins, particularly 2-hydroxypropyl-β-cyclodextrin (HPβCD), are widely used to enhance the solubility and stability of poorly soluble drugs.
• Carbopol® gels are common matrices for topical drug delivery, requiring compatibility with active pharmaceutical ingredients and excipients.

Purpose of the Study:

• To prepare and characterize a curcumin/HPβCD inclusion complex.
• To evaluate the antioxidant and antimicrobial activities of curcumin and its inclusion complex.
• To assess the impact of curcumin and its inclusion complex on the textural and rheological properties of Carbopol® gel for potential topical applications.

Main Methods:

• Curcumin/HPβCD inclusion complex synthesized via co-precipitation (1:1 molar ratio).
• Antioxidant activity assessed using DPPH, ABTS, and FRAP assays.
• Antimicrobial activity evaluated using the micro-dilution method.
• Textural, rheological, and morphological properties of Carbopol® gels (with and without curcumin/complex) analyzed using a texturometer and SEM.

Main Results:

• The curcumin/HPβCD inclusion complex exhibited superior antioxidant and antimicrobial activities compared to free curcumin.
• Scanning Electron Microscopy (SEM) confirmed the presence of curcumin and the inclusion complex within the Carbopol® gel matrix.
• Rheological analysis indicated that the inclusion complex did not compromise the structural integrity of the Carbopol® gel.
• Textural analysis revealed no significant changes in gel properties upon addition of curcumin or its inclusion complex.
• The highest swelling degree was observed in the gel formulation containing dispersed curcumin (Gel 3).

Conclusions:

• The prepared curcumin/HPβCD inclusion complex demonstrates enhanced bioactivity and good compatibility with Carbopol® gel.
• The findings suggest that the curcumin/HPβCD inclusion complex is a promising candidate for topical formulations.
• Further studies are warranted to optimize formulation parameters and evaluate in vivo efficacy for dermatological applications.