AHPA condemns Class 1 solvents in herbals manufacturing

10-Aug-2011 - Last updated on 11-Aug-2011 at 14:55 GMT

So-called Class 1 solvents such as benzene and carbon tetrachloride have no place in the manufacture of herbal products, the American Herbal Products Association (AHPA) has said.

In revamping its guidance on the solvents, AHPA said toxicity and environmental concerns could not be ignored, even though the International Conference on Harmonization (ICH) permits them in certain usually pharmaceutical situations.

Its new guidance policy states Class 1 solvents including 1,2-dichloroethane; 1,1-dichloroethene; and 1,1,1-trichloroethane, "are not appropriate for use, and should not be used, in the manufacture of herbal extracts."

While compliance with the guidelines is not a prerequisite of AHPA membership in the same way its trade recommendations are, the AHPA strongly encouraged its members to fall into line with the guidance.

"The previous AHPA policy did not explicitly exclude class 1 solvents as ICH makes exemptions for their use in drug manufacture when no other solvents can be used," said Steven Dentali, PhD, AHPA's chief science officer in a statement.

"AHPA's Standards Committee, which recommended the new policy to the board, wanted to make it clear that these solvents have no place in the manufacture of herbal extracts due to their unacceptable toxicity or status as an environmental hazard. Most of the solvents listed are not used in the manufacture of herbal extracts; AHPA acted to harmonize with the broadly accepted ICH guidelines."

Asetic acid residues

AHPA has also revised its guidance for acetic acid residues.

Dentali said it had, “recognized that some liquid extracts should have an exemption for acetic acid residues when they are formulated with acetic acid or vinegar – which contains acetic acid – in the same way that the earlier guidance policy exempted residual ethanol when it is used as a component in the manufacture of liquid extracts."

It encouraged both AHPA members and non-members, “to adopt each of these policies in the interest of establishing consistent and informed trade practices.”