The most significant challenge that the pharmaceutical field is currently facing is the low bioavailability of the drugs, mostly due to their poor aqueous solubility and dissolution rates. The supercritical fluid (SCF) technology is an environmentally-friendly alternative to conventional techniques for preparing drug delivery systems, which can tremendously improve the bioavailability of the drugs and protect them from hard conditions such as temperature, oxygen and pH, so enhancing their stability. The tunable properties of the supercritical fluids allow the SCF technologies to produce modified final products, based on the desired application. The supercritical CO2 is the most used SCF, due to its mild supercritical conditions, inexpensiveness, chemical stability, non-flammability, and non-toxicity.