THIAMPHENICOL CONTAINS NOT LESS THAN 98.0 PER CENT AND NOT MORE;THAN THE EQUIVALENT OF 100.5 PER CENT OF 2,2-DICHLORO-N-【(1R, 2R);-2-HYDROXY-1-(HYDROXYMETHYL)-2-【4-(METHYLSULPHONYL) PHENYL】ETHYL;】ACETAMIDE, CALCULATED WITH REFERENCE TO THE DRIED SUBSTANCE.