Irinotecan Hydrochloride Trihydrate Imp. F (EP):(4S)-4,11-diethyl-4-hydroxy-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione [ 11-ethylcamptothecin (EP) or 7-Ethylcamptothecin (USP)].