An approach to the improvement of dissolution rate of inclusion complex of vat red 13 with β-cyclodextrin

The dissolution rate of hydrophobic dyes like Vat Red 13 poses a significant challenge in Vat dyeing processes due to their poor solubility in aqueous media. This study explores the formation and characterization of an inclusion complex between Vat Red 13 (VR13) and beta-cyclodextrin (beta-CD) to enhance its dissolution rate. The solid inclusion complex is prepared using two distinct techniques: physical mixture, and encapsulation by adopting a molar ratio 1:1. The enhancement of inclusion complex solubility in the liquid state was examined using the UV-Vis absorption spectrum values. The solid inclusion complex was characterized using transmission electron microscope, Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffraction, and contact angle analysis. Results demonstrated a significant increase of absorption as well as obvious solubility of beta-CD/VR13 compared to conventional VR13. The enhanced dissolution rate can be attributed to the encapsulation of VR13 into the hydrophobic cavity of beta-cyclodextrin, which facilitates better interaction with the solvent. Moreover, the disruption of its crystalline structure, which led to the generation of more amorphous regions. The beta-CD/VR13 inclusion complex minimized the amount of reducing agent needed by approximately 75% and sped up the vat dyeing process on viscose fabric. This approach offers a promising solution for improving the dyeing efficiency of Vat dyes in textile applications.