Design of plant-based bigels by incorporating candelilla wax oleogel and xanthan gum hydrogel for oral curcumin delivery.

This study evaluated the role of plant-based biphasic gel (bigel) formulations prepared using various ratios of xanthan gum (XG) hydrogel and Candelilla wax-based oleogel for the delayed release of curcumin (CUR). Microscopic studies revealed that the bigel exhibited a bicontinuous phase distribution. FTIR analysis suggested increased hydrogen bonding with a higher proportion of hydrogel in the bigel formulations. The percentage of stress-relaxation in the mechanical study decreased as the hydrogel proportion was increased within the formulations, indicating a rise in elastic components (89.84-27.10 %; CX1-CX5). An examination of the electrical characteristics of the bigels showed an increase in impedance values with higher oleogel concentration (1.2 × 10-1.0 × 10; CX1-CX5). An in vitro release study showed a delayed release in the bigel (31.96 to 24.90 %), whereas the control formulation showed a release of 43.43 % at the end of the experiment. The control formulation showed an anomalous diffusion pattern, whereas bigel formulations exhibited Fickian diffusion-mediated release kinetics. As per the ex vivo intestinal permeation study, the drug was released from the gel formulations through Fickian diffusion (CX1, CX2, and CX4) and anomalous diffusion (CX3 and CX5). The stability study, evaluated by the heat-cool method, confirmed that the dosage form was stable after 6 cycles.