Production of herbal nanocolloids from Rubia tinctorum L. roots by rapid expansion from supercritical solution into suspension system

The current study was done to confirm the existence of stable nanoparticles of phyto-compounds, such as alizarin, lucidin, and rubiadin from Rubia tinctorum L. roots by employing the supercritical procedure. These compounds have a low bioaccessibility since; they are rarely soluble in aqueous media. Hence, preparation of a stable colloid of herbal extract in a nano suspension system can resolve this problem by reducing particle size. Moreover, central composite design (CCD) was exploited for analyzing the effect of pressure, CO2 flow rate, modifier volume, and oven temperature on antioxidant activity index (AAI) following application of supercritical procedure. Furthermore, dynamic light scattering (DLS), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and liquid chromatography–mass spectrometry (LCMS) techniques were utilized to appraise properties of the prepared nanocolloids. Based on the results, demeanor of the particles changed after particle creation, demonstrating that the supercritical procedure results in the diminished accumulation of the particle and raising AAI for the extract. Hence, bioaccessibility of medicinal herb can be significantly enhanced in biological media and in -vitro testing determined their valuable antioxidant properties by comparison with standards and classifications.