Colloidal curcumin-laden pH-responsive hydrogels: A promising approach to enhance solubility, dissolution, and permeation of hydrophobic drug

Oral drug delivery systems have innumerable advantages, despite their precedence, the delivery of lipophilic drugs belonging to biopharmaceutical class II and IV, which has challenges associated with their solubility and permeability, leading to the limitations of this route. To address these barriers, nanocarrier systems combined with biomaterials are considered one of the pre-eminent approaches. Therefore, in this study pH-responsive pullulan-based hydrogels were developed, which were loaded with curcumin nanocrystals, micelles and coarse curcumin. In-vitro characterization studies, including dynamic light scattering, Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction supported the development of hydrogels. The swelling index showed that developed hydrogels have significant swelling at pH 7.4, as the optimized formulation shows a q value of 5.938% at higher pH and 2.382% at lower pH. Additionally, the nanocrystal-laden hydrogel showed 86.250% drug release at pH 7.4, and better release than micelles and coarse curcumin-laden hydrogel. Moreover, nanocrystals showed a 1-fold increase in the solubility of curcumin, enhanced physical stability, and 82.81% permeation as compared with formulations. Conclusively, the outcome of the studies distinctly revealed a promising approach for successfully developing Pu-g-MAA hydrogels and the inclusion of lipophilic drugs in them.

Automated summary

This study developed pH-responsive pullulan-based hydrogels loaded with curcumin nanocrystals, micelles, and coarse curcumin. In-vitro characterization studies support the development of hydrogels. The hydrogels showed significant swelling at pH 7.4, with the optimized formulation exhibiting q values of 5.938% at higher pH and 2.382% at lower pH. Nanocrystal-laden hydrogel exhibited 86.250% drug release at pH 7.4 and better release compared to micelles and coarse curcumin-laden hydrogel. Nanocrystals also showed enhanced solubility, physical stability, and permeation. The study demonstrated a promising approach for developing Pu-g-MAA hydrogels and incorporating lipophilic drugs.