title: Kinetic spectrophotometric method for the determination of ranitidine and nizatidine in pharmaceuticals.
abstract: An accurate and simple kinetic method is described for the determination of ranitidine and nizatidine in pure form and in pharmaceuticals. The method is based on the reaction of the compounds with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole in pH 7.4 borate buffer at 60 degrees C for a fixed time of 25 min for both compounds. The absorbance of the reaction product is measured at 495 nm for ranitidine and nizatidine. Calibration graphs were linear over the concentration range of 2-20 microg/mL, with limits of detection of 0.13 (3.7 x 10(-7) M) and 0.25 microg/mL (7.5 x 10(-7) M) for ranitidine and nizatidine, respectively. The proposed method was applied successfully to the determination of ranitidine in tablets and ampoules with average recoveries of 100.26+/-0.69 and 100.29+/-0.59%, respectively, and to the determination of nizatidine in capsules with an average recovery of 104.26+/-0.44%. The results obtained are in good agreement with those obtained by the other methods used for comparison. A proposal of the reaction pathway is also presented.
authors.affiliation: University of Mansoura, Faculty of Pharmacy, Department of Analytical Chemistry, Egypt.
authors.forename: Mohamed I
authors.initials: MI
authors.lastname: Walash
authors.forename: Fathalla
authors.initials: F
authors.lastname: Belal
authors.forename: Fawzia
authors.initials: F
authors.lastname: Ibrahim
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hefnawy
authors.forename: Manai
authors.initials: M
authors.lastname: Eid
mesh_terms: D002138:Calibration; D002214:Capsules; D006635:Histamine H2 Antagonists / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D016567:Nizatidine / Q000032:analysis*; D011899:Ranitidine / Q000032:analysis*; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets
chemical_list: D002214:Capsules; D006635:Histamine H2 Antagonists; D007202:Indicators and Reagents; D012996:Solutions; D013607:Tablets; D011899:Ranitidine; D016567:Nizatidine