title: Stability indicating spectrophotometric and spectrodensitometric methods for the determination of diatrizoate sodium in presence of its degradation product.
abstract: Three sensitive, selective, and precise stability indicating methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA), in the presence of its acidic degradation product (highly cytotoxic 3,5 diamino metabolite) and in pharmaceutical formulation were developed and validated. The first method is a first derivative (D1) spectrophotometric one, which allows the determination of DTA in the presence of its degradate at 231.2 nm (corresponding to zero crossing of the degradate) over a concentration range of 2-24 μg/mL with mean percentage recovery 99.95±0.97%. The second method is the first derivative of the ratio spectra (DD1) by measuring the peak amplitude at 227 nm over the same concentration range as D1 spectrophotometric method, with mean percentage recovery 99.99±1.15%. The third method is a TLC-densitometric one, where DTA was separated from its degradate on silica gel plates using chloroform:methanol:ammonium hydroxide (20:10:2 by volume) as a developing system. This method depends on quantitative densitometric evaluation of thin layer chromatogram of DTA at 238 nm over a concentration range of 4-20 μg/spot, with mean percentage recovery 99.88±0.89%. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt.
authors.forename: Mohamed K
authors.initials: MK
authors.lastname: Abd El-Rahman
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt.
authors.forename: Safaa M
authors.initials: SM
authors.lastname: Riad
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt.
authors.forename: Sherif A
authors.initials: SA
authors.lastname: Abdel Gawad
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt. Electronic address: esraafawaz_2007@yahoo.com.
authors.forename: Esraa M
authors.initials: EM
authors.lastname: Fawaz
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El Aini Street, 11562 Cairo, Egypt.
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: Shehata
mesh_terms: D002855:Chromatography, Thin Layer; D003720:Densitometry / Q000379:methods*; D003973:Diatrizoate / Q000032:analysis* / Q000737:chemistry; D011208:Powders; D013053:Spectrophotometry / Q000379:methods*; D013055:Spectrophotometry, Infrared
chemical_list: D011208:Powders; D003973:Diatrizoate
keywords: Derivative spectrophotometry; Sodium diatrizoate; Stability indicating methods; TLC-densitometry