Processing of Curcumin by Gas Antisolvent (GAS): Morphological and Structural Effects

Curcumin is a polyphenol extensively studied for its anti-inflammatory and antioxidant activities; however, its pharmaceutical performance is limited by poor water solubility. In view of these limitations, particle engineering techniques based on supercritical fluid technology have emerged as clean and effective approaches to modify its physicochemical properties. Among these techniques, gas antisolvent (GAS) processing enables particle size reduction and solid-state modification without inducing chemical degradation. In this study, commercial curcumin was dissolved in acetone (10 mg·mL^-1) and processed by the GAS method at 80 bar and 35 °C, followed by drying under a CO₂ flow of 10 mL·min^-1. The resulting particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Commercial curcumin exhibited well-defined, smooth-surfaced prismatic particles, typical of highly crystalline materials. After GAS processing, a statistically significant reduction in mean particle size was observed, from 17.15 ± 10.81 µm to 12.22 ± 8.11 µm (p < 0.00001), along with morphological changes and the onset of a less ordered structural behavior. XRD analysis indicated preservation of the characteristic diffraction reflections, accompanied by a partial reduction in crystallinity. FTIR spectra confirmed the maintenance of curcumin’s characteristic vibrational bands, demonstrating the absence of chemical degradation or structural transformation. These results indicate that GAS processing is a robust and environmentally friendly strategy for modifying the physical state of curcumin while preserving its molecular integrity.