Determination of Nifedipine drug in Pure and Pharmaceutical Preparations by Normal Flow Injection Analysis using Sulfamethaxazole Drug as Chromogenic Reagent

A highly sensitive and accurate spectrophotometric method including Technique ( Normal Flow injection analysis have been used for determined Nifedipine (NIF) drug in pure dosage forms. This approach based on the response of with diazotized sulfamethoxazole (SMZ) to form colored product after diazotization reagent coupling reaction The coloured chromogen suggests absorption maximum at 496 nm. line conditions had investigated by (1) invariable chemical approach, optimizing impact experimental variables (special bases, awareness, time), (2) physical methods effect three factors (injection loop length , coil ,flow rate time). results gave Beer's law is obeyed over awareness range 2-180 μg. ml-1 an excellent determination coefficient (r2= 99.97) molar absorptivity 3428.714. stoichiometry resulting azo dye has also worked out it found be 1:1 Nif: SMZ. carried successfully pharmaceutical preparations (tablets). Keywords: Nifidipine flow analysis, spectrophotometry, Sulfamethoxazol ، diazotization.