Definition: An acid-base indicator which is colorless in acid solution, but turns pink to red as the solution becomes alkaline. It is used medicinally as a cathartic.
Other names Thompson Brand of Phenolphthalein; Schering-Plough Brand of Phenolphthalein; Novartis Brand of Phenolphthalein; Thalinol; Modane; Mentholatum Brand of Phenolphthalein; Manesco Brand of Phenolphthalein; Laxettes; Laxatone; Key Brand of Phenolphthalein; Feen-A-Mint; Ex-Lax; Ap-La-Day