Process for extracting the active principles from senna

摘要

The active principles of senna leaf or pods (with or without seeds) are extracted by an aqueous organic solvent in which they are soluble to which an acid is added. The acid may be inorganic e.g. hydrochloric, or organic e.g. citric. Preferred solvents are methanol, ethanol and acetone. The acid macerate may be neutralised with ammonia, evaporated under reduced pressure to remove the solvent and the concentrate dried by spreading it thinly on plates, trays or drums at atmospheric temperature in a low humidity chamber. Alternatively, undiluted organic solvent and a base may be added to the macerate to precipitate the active principles which may be filtered and dried. The powder may be incorporated into tablets, pastilles, lozenges or granules. If desired, the excipient or carrier may be added to the concentrate prior to drying.