to aqueous and alcoholic aqueous primary extracts extract fraction b according to the invention is characterised by the depletion of more lipophilic or the enrichment of more hydrophilic compounds respectively this depletion or enrichment is expressed by a clearly increased mono cqa content and a greatly increased mono cqa flavonoid quotient see fig1 and compare table 3 with table 7 total cqa contents of at least 1 usually of 2 to up to 10 are found when using aqueous primary extracts and usually 3 to 15 when using alcoholic aqueous primary extracts regardless of the primary extraction agent the mono cqa content of the total cqa content is at least 70 for example at least 75 and generally over 75 to 85 the flavonoid content of extract fraction b is a maximum of 2 preferably 0 02 to 1 5 for aqueous and alcoholic aqueous primary extracts regardless of the primary extraction agent the mono cqa flavonoid quotient in fraction b is increased to values of between 4 and 35 for example between 5 and 35 as compared to the primary extract examples of results for four fractionations of primary extracts from high grade drugs carried out according to the invention examples 8 to 11 are given in table 7 the extraction agent in the method according to the invention is a non aqueous extraction agent such as an.