Since the "reaction stop" incident, countries have started to pay attention to the pharmacological activity of isomers in chiral drugs because of the different activities of different isomers. The main chiral dismantling methods are:
Crystallization
Chemical cleavage
Biological dismantling
Chromatographic methods, including gas chromatography, for the separation of volatile chiral substances; high performance liquid chromatography (HPLC), which uses a chiral stationary phase with good stability, is an important chiral separation method; supercritical fluid chromatography (SFC), which is environmentally friendly, highly efficient, has a large sample throughput and low cost, has increasingly replaced HPLC as the first choice for chiral separation.
Preparative high-performance liquid chromatography (Prep HPLC) has been one of the most commonly used purification techniques for over 20 years. Specifically, it is a popular separation process in the fine chemicals, pharmaceutical, and biotechnology industries and is widely used in product purification operations. Over this time, Prep HPLC has developed into a fairly effective and applicable technique, particularly for non-chiral purifications.
Although popular, Prep HPLC has several drawbacks. The volume of the mobile phase required to purify a specified mass of the compound is large compared to the total sample volume being processed. A typical Prep HPLC fraction contains a large amount of solvent (organic and aqueous) and because of the time required to dry and collect the final product a major advantage of Prep SFC is that the use of CO2 replaces most of the mobile phase, saving solvent usage. This is a major advantage of Prep SFC, as it uses CO2 to replace most of the mobile phase, saving solvent use and effort.
A major advantage of Prep SFC is that it uses CO2 instead of most of the mobile phase, saving solvent usage and making it greener. In SFC purification system, the separation efficiency is better due to the low viscosity and high diffusion rate of the mobile phase, allowing for faster and more efficient chromatographic separations.