On 15 January 2013, the EMA published the HMPC "Concept Paper" on the use of recovered / recycled solvents in the manufacture of herbal medicinal products / traditional herbal medicinal products. Recovered / recycled solvents are mainly used for extraction of herbal substances in the manufacture of herbal preparations.
Now, this raises the question of which standards should be used for these solvents. Which criteria must be taken into account?
The quality of solvents is a critical factor in the manufacture. The control of solvents must be appropriate and adapted to the intended purpose in order to ensure batch to batch reproducibility.
Besides water, the following examples are mentioned: ethanol, methanol, acetone, ethyl acetate, hexane and dichloromethane.
From a GMP (for API manufacturers) point of view, the use of recovered solvents is basically acceptable. Also the European Pharmacopoeia has comparable regulations.
The "Concept paper on use of recovered/recycled solvents in 4 the manufacture of herbal preparations for use in herbal 5 medicinal products / traditional herbal medicinal products" now recommends developing a guideline on the standards to be applied to recovered / recycled solvents.