| dc.description.abstract | Cannabis sativa is one of the oldest plant cultures, which has been used for centuries as a source of textile fibres, for paper production, as well as a source of bioactive compounds used in medicine. Although being restrained for a long time, its high potential, coupled with the progress in legislation and/or legalization in some regions of the world, led to the significant increase of scientific research towards isolation of cannabinoids, primarily a non-psychotropic cannabidiol (CBD), over the past couple decades.
Beside cannabinoids, found only in cannabis plants, Cannabis sativa is characterized by very complex chemical composition with almost 500 constituents, including terpenes, flavonoids, phenolic compounds and fatty acids [2]. The co-presence of these numerous molecules in preparations obtained from Cannabis sativa may lead to a greater biological activity due to the “entourage” or synergistic effect [3]. CBD has attracted considerable interest due to its numerous therapeutic properties and pharmacological activities [1]. However, cannabinoids are characterized by a low solubility in aqueous media and, as a consequence, a relatively poor bioavailability. Therefore, improvement of their stability, shelf-life and bioavailability, by incorporation into biocompatible carriers is still a challenge.
As an answer to this issue, integrated process of supercritical fluid extraction (SFE) from Cannabis sativa and supercritical solvent impregnation (SSI) of obtained extract into starch aerogel was tested. Starch gels were prepared starting from hydrogel formed from an aqueous solution of cornstarch (1:10 w/v). During replacement of water with acetone, by successive increase of its concentration until 100%, acetogel was formed and further subjected to drying using supercritical CO2 (scCO2) at 45 °C and 8-10 MPa to obtain aerogel. For comparison, a part of acetogel was dried in the oven at 60 °C to obtain xerogel. Textural properties and morphology of prepared materials were determined by N2 adsorption–desorption isotherms and scanning electron microscopy (SEM) analysis. Aerogel with highest specific surface area of 208.6 m2/g, obtained at 45 °C and 10 MPa, was further used for extract impregnation. Integrated SFE-SSI process was performed at 40 °C and 10 MPa, conditions determined as optimal in the process of SFE of Cannabis sativa taking into account the yield of the obtained extract based on the composition, primarily regarding the CBD content. The amounts of impregnated extracts were 2.6 and 15.3% for xerogel and aerogel, respectively. The presence of the extract on the surface of impregnated samples was confirmed by FTIR analysis. Release study showed controlled release of extracts in PBS solution. | sr |
