title: Sensitive assay procedure for ethambutol hydrochloride via charge transfer complex formation.
abstract: The charge transfer complex formation between ethambutol and iodine was investigated and utilized as the basis for a sensitive spectrophotometric procedure for ethambutol and its dosage forms. The solutions exhibited blue-shifted iodine bands at 293 and 360 nm. A Job's plot of corrected absorbance against the mole ratio of ethambutol to iodine indicated a 1:2 drug-iodine ratio. At 293 nm, the absorbance was linear (r=0.9998) over the 0.25-15-microgram/ml concentration range, but the concentration range for best accuracy is 1.6-5.8 microgram/ml. The method can be applied successfully to the analysis of commercially available ethambutol tablets.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D004977:Ethambutol / Q000032:analysis*; D007455:Iodine; D008722:Methods; D011208:Powders / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets / Q000032:analysis; D013997:Time Factors
chemical_list: D011208:Powders; D013607:Tablets; D004977:Ethambutol; D007455:Iodine