Spectrophotometric Determination of Nifedipine in Pharmaceutical Tablets Using Batch and Flow Injection Method Via Diazotization Coupling Reaction

Batch and Flow injection analysis (FIA) spectrophotometric Method have been presented for determination of nifedipine (NIF)in pure and pharmaceutical forms. The Method were based on the diazotization coupling reaction of NIF with diazotized p-nitro aniline (DPNA)in the presence of alkaline medium. Red product was formed and measured at l_max509 nm. All optimum conditions were studied for each method. Linearity of NIF was observed for batch 20–100 μg.mL⁻¹ and for FIA5–120 μg.mL⁻¹ and the detection limits were 4.197, 1.326 μg.mL⁻¹ for batch, FIA respectively. The method offered a good sensitivity, accuracy and precision; FIA was more convenient than batch method because of the wider linear range moreover, the sampling rate was 28 injections per hour but less reproducibility than batch method. A comparison study was carried out between the proposed and standard Method by calculating students’ t-test and F-test indicated no significant differences between them, the suggested method could be utilized for pharmaceutical analysis.