Aqua Hamamelidis. U. S. (Br.) Hamamelis Water.
Aq. Hamam. [Witch Hazel Water, Distilled Extract of Witch Hazel]
Related entries: Hamamelis
Liquor Hamamelidis, Br.; Solution of Hamamelis, Witch-hazel extract; Eau distillee de hamamelis, Fr.; Hamamelis-wasser, G.
"A saturated aqueous liquid obtained by distilling with steam or water the bark, twigs, smaller stems or the entire shrub of Hamamelis virginiana Linne (Fam. Hamamelidaceae) collected in the autumn, and adding one hundred and fifty mils [or 5 fluidounces, 35 minims] of alcohol to each eight hundred and fifty mils [or 28 fluidounces, 356 minims] of distillate. Preserve it in tightly-closed containers in a cool place." U. S. "Fresh Hamamelis Leaves, 1000 grammes; Distilled Water, 2000 millilitres; Alcohol (90 per cent.), 160 millilitres. Macerate for twenty-four hours; then distil one thousand millilitres." Br.
The U. S. P. VIII directed that this water be made from Hamamelis Bark, the Br. Pharm. (1914) directs fresh Hamamelis leaves; the U. S. P. IX uses the bark, twigs, smaller stems, or the entire shrub of Hamamelis.
Hamamelis Water or, as it is popularly called, "Distilled Extract of Witch Hazel," has been found on the market containing very little alcohol, formaldehyde being used as a preservative. Methyl alcohol has also been found in place of ethyl alcohol in many samples. The U. S. Pharmacopoeia IX describes Hamamelis Water as "a clear and colorless, or not more than faintly opalescent or slightly yellowish liquid having a characteristic odor and taste. It is neutral or only faintly acid to litmus. Specific gravity: 0.979 to 0.982 at 25° C. (77° F.). It must be free from mucoid or fungous growths and must not have an acetous odor. It gives no reaction with hydrogen sulphide T.S. or with sodium sulphide T.S. (metallic impurities). Evaporate 100 mils of Hamamelis Water to dryness on a water bath; not more than 0.025 Gm. of residue remains (dissolved impurities). It contains not less than 14 per cent. of absolute alcohol, by volume, when estimated as directed under Determination of alcohol in official preparations (see Part III, Test No. 14). Add 8 drops of an aqueous solution of resoreinol (1 in 200) to 5 mils of Hamamelis Water and then carefully pour this upon 5 mils of sulphuric acid, contained in a test tube, in such a manner that the two liquids do not mix. After standing for three minutes a rose-red ring does not appear at the line of contact of the liquids nor does a distinct, white layer appear above this zone (formaldehyde). Ten mils of Hamamelis Water gives no reaction for methyl alcohol when tested as directed under Alcohol for the detection of methyl alcohol."U. S.
Uses.—This water was probably introduced into the British Pharmacopoeia and U. S. Pharmacopoeia IX on account of the large demand for it which has grown out of the wide advertisements of a certain proprietary medicine, and the universally recognized need in American families for an embrocation which appeals to the psychic influence of faith. As the tannic acid of hamamelis bark does not come over into the distillate the water is therapeutically a mixture of water and alcohol, the volatile oil being found in too minute a proportion to possess any therapeutic value.