Spectrophotometric Determination of Sulfamethoxazole in Pure and in Pharmaceutical Preparations by Diazotization and Coupling Reaction

Abstract

A highly sensitive, simple and accurate spectrophotometric method has been developed for quantitative determination of sulfamethoxazole(SMX) in both pure form and pharmaceutical preparations. In this method SMX is diazotized with equimolar of sodium nitrite(NaNO 2) in acid medium of hydrochloric acid to form diazonium ion , which is reacted with 2,4,6-trihydroxybenzoic acid in alkaline medium of NaOH to form a yellow water soluble azo dye that has absorption maximum at 416 nm versus reagent blank. Beer's law is obeyed over the concentration range 0.2-16 µg. ml-1 with an excellent determination coefficient (r 2 = 0.9996) and molar absorptivity 1.84×10 4 l.mol-1 .cm-1. The recoveries are obtained in the range of 97.8-99.8% and the relative standard deviation is better than ±0.23%. The stoichiometry of the resulting azo dye has been also worked out and it is found to be 1:1 SMX: 2,4,6-trihydroxybenzoic acid. This method has been applied successfully for the determination of SMX in pharmaceutical preparations (tablets and oral suspension).

Synthesis and Characterization of New Azo Dye Derived from Sulfamethaxolevia Diazonium Reaction and Study its Abilityas an Acid-base Indicator

“…S ulfamethoxazole(SMZ) is a member of the sulfonamide family of antibacterials and the chemical name is 4-Amino-N-(5-methyl-3-isoxazolyl)-benzene sulfonamide [1]. It is one of many antibiotics [2].…”

“…It is one of many antibiotics [2]. A survey of the literature showed that different techniques have been reported for SMZ analysis, some of which include spectrophotometric methods [1], for instance, HPLC [3], electrochemical methods [4] an solid phase extraction [5]. Diazotization method is simple and inexpensive method.…”

Development of Spectrophotometric Method for The Determination of Mesalazine as Pure Form and in Tablets

“…Most of the aforementioned procedures involved oxidative coupling reactions with thymol in the existence of sodium meta periodate (Salih & Mohammed, 2020), phenothiazine in the presence of potassium sulphate (K2SO4) as oxidant (Shehab & Muhammed, 2020), pyrocatechol and K2SO4 (Shihab, 2011), histidine in the presence of N-bromosuccinimide (NBS) (Zakaria, 2019), 8-hydroxyquinoline and N-(1-naphthyl) ethylenediamine (NNED) in alkaline solution (Zakaria, 2013). Others depended on the diazotization reaction of MESZ and coupling with some reagents for instance, 2,6-dihydroxytoluene (Aziz & Sultan 2019), resorcinol (Madhavi et al, 2011) and phlorogycinol (Hamdon et al, 2012). A condensation reaction was also applied to estimate MESZ via spectrophotometric methods by using reagents of salicylaldehyde (Anumolu et al, 2019) and pdimethylaminocinnamaldehyde (Sama et al, 2011).…”

A Novel Spectrophotometric Determination and Kinetic Study of Sulfamethoxazole in Pure and Tablet Formulation using 9-chloroacridine Reagent

“…These techniques are expensive and need special training. Also, spectrophotometric methods have been reported for determination of SMX using different reagents such as, vanillin [10], 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, p-chloranil and picric acid [11], phenoxazine [12], 2,4,6-trihydroxybenzoic [13], 1-naphthol [14], 2-naphthol [15], Salbutamol sulphate [16], thymol [17], and Diphenylamine [18]. Some of these methods are disadvantageous, in terms of sensitivity, and require extraction or heating steps.The present study is developing a new sensitive and simple spectrophotometric method for determination of SMX in pure and dosage forms, depending on formation of a new product by the reaction of SMX with 9-chloroacridine (9-CA).…”