A fluid in a supercritical state is one that has been subject to conditions above their critical pressure and temperature parameters and which have corresponding intermediate properties - between those of a liquid and of a gas, and with ideal solvent properties.
One of the most recent projects developed at GAIKER in relation to this theme is that of CEREX (Obtaining Wool Ceramides by means of Supercritical Fluids Extraction) using sheep's wool.
This has provoked great interest in the pharmaceutical and cosmetics industries given that the ceramides currently used are prepared using synthetic and biotechnological methods, with concomitant very high costs. Moreover, ceramides obtained following these techniques do not possess the same chemical composition as those present in the skin.
Ceramides that repair skin tissue
The ceramides present in wool, however, are very similar in composition to those found on the corneal layer of human skin tissue. This, fundamentally proteinaceous, natural fibre has an external lipid content – known as lanolin - already used in cosmetics – and an internal lipid content of great value due to its high concentration of ceramides.
The process of extraction with supercritical CO2 developed at GAIKER enable high-yield extractions of wool ceramides, and the studies undertaken by IIQAB of the extracted lipids have show that the liposomic structures formed with them provide a reinforcement of the protective barrier function of the skin, increasing its hydration and accelerating its repair when the tissue has been chemically or physically damaged. Although there are a number of supercritical fluids, the fluid most used at both research and industrial applications levels is undoubtedly CO2. This is because its critical conditions are relatively low (31ºC, 73 atm) and, therefore, easy to operate.