Araroba, B.P. Araroba.
Related entry: Chrysarobin
Synonyms.—Crude Chrysarobin; Goa Powder.
Araroba is a substance found in the trunk of Andira Araroba, Aguiar (N.O. Leguminosae), a large tree growing in the damp forests of Bahia (Brazil). It is scraped out of the cavities together with woody debris, and is exported in a crude and moist condition as an umber-brown powder, containing numerous fragments of wood. It is roughly freed from the moisture and much of the woody debris by drying and sifting, and may be further purified by exhausting with hot chloroform or benzene, evaporating the solution to dryness, and powdering the residue. It is stated, however, that by this method an active constituent insoluble in chloroform and benzene is left in the drug. Another method of purification is to boil the crude drug with solution of caustic potash, filter, and reprecipitate by acidifying the dark coloured solution with hydrochloric acid. The drug occurs as a brownish-yellow to dark brown powder, which should yield not less than 50 per cent. to hot chloroform, while as much as 75 per cent. is sometimes obtained.
Constituents.—Purified araroba consists largely of chrysarobin, but also contains dichrysarobin, the methyl ether of dichrysarobin, and a fourth substance which awaits further investigation; all of these are soluble in chloroform. Crude araroba contains in addition to these substances from 15 to 30 per cent. of moisture and varying quantities of woody debris.
Action and Uses.—Araroba resembles chrysarobin in its properties; in India, crude araroba is preferred to chrysarobin. For its action in psoriasis see under Chrysarobinum. In tropical countries it is applied mixed with lime juice or with vinegar. Araroba is used officially as the source of chrysarobin, but it has been asserted to be more efficacious than the latter, owing to the presence of an unknown active substance, which is not extracted by chloroform.
PREPARATION.
- Unguentum Ararobae, B.P.C.—ARAROBA OINTMENT.
- Araroba, 1; glacial acetic acid, 1; lard, 14. Used as a stimulant and parasiticide in psoriasis, acne rosacea, and ringworm. It may be diluted with an equal quantity of lard when used for tender skins.
