The herbal preparations can be in {HEAD ~ the form} of extracts, powders, distillates, infusions, {TAIL ~ tinctures}, and oils 
of
The herbal preparations can be in { HEAD ~ the form } of extracts , powders , distillates , infusions , { TAIL ~ tinctures } , and oils
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH