title: Utility of oxidation-reduction reaction for the determination of ranitidine hydrochloride in pure form, in dosage forms and in the presence of its oxidative degradates.
abstract: Three simple, accurate and sensitive colorimetric methods (A, B and C) for the determination of ranitidine HCl (RHCl) in bulk sample, in dosage forms and in the presence of its oxidative degradates are described. The first method A is based on the oxidation of the drug by N-bromosuccinimide (NBS) and determination of the unreacted NBS by measurement of the decrease in absorbance of amaranth dye (AM) at a suitable lambda(max)=520 nm. The methods B and C involve the addition of excess Ce(4+) and determination of the unreacted oxidant by decrease the red color of chromotrope 2R (C2R) at a suitable lambda(max)=528 nm for method B or decrease the orange pink color of rhodamine 6G (Rh6G) at a suitable lambda(max)=526 nm for method C. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 0.2-3.6, 0.1-2.8 and 0.1-2.6 microg ml(-1) for methods A, B and C, respectively. The apparent molar absorptivity. Sandell sensitivity, detection and quantitation limits were calculated. For more accurate results, Ringbom optimum concentration ranges were 0.3-3.4, 0.2-2.6 and 0.2-2.4 microg ml(-1) for methods A, B and C, respectively. Analyzing pure and dosage forms containing RHCl tested the validity of the proposed methods. The relative standard deviations were </=1.38 with recoveries 98.9-101.0%.
authors.affiliation: Department of Chemistry, Faculty of Science, Benha University, Benha, Egypt. asamin2002@hotmail.com
authors.forename: A S
authors.initials: AS
authors.lastname: Amin
authors.forename: I S
authors.initials: IS
authors.lastname: Ahmed
authors.forename: H A
authors.initials: HA
authors.lastname: Dessouki
authors.forename: E A
authors.initials: EA
authors.lastname: Gouda
mesh_terms: D001965:Bromides / Q000737:chemistry; D001974:Bromosuccinimide / Q000737:chemistry; D002563:Cerium / Q000737:chemistry; D004396:Coloring Agents / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000032:analysis / Q000737:chemistry; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D011899:Ranitidine / Q000032:analysis* / Q000737:chemistry*; D012044:Regression Analysis; D013053:Spectrophotometry / Q000379:methods; D013431:Sulfates / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D001965:Bromides; D004396:Coloring Agents; D006635:Histamine H2 Antagonists; D017680:Potassium Compounds; D013431:Sulfates; C107379:cerium sulfate; D002563:Cerium; D011899:Ranitidine; D001974:Bromosuccinimide; C039004:potassium bromide; D010100:Oxygen