New CFIA / Merging Zones Technique for Determination of Captopril in Pure and Pharmaceutics Dosage forms through the Oxidation / Reduction Reaction of Drug with Cu(II)- Neocuproine Complex via Spectrophotometric Detection

A new simplicity, accuracy, rapid and sensitive batch and merging zones-flow injection analysis spectrophotometric ways for estimation of captopril in fine material forms and pharmaceutical formulations were suggested. The procedure was depended on the oxidation and reduction reaction of CPL with Cu (II) Neocuproine complex as reagent in presence of acetate buffer solution (pH=5) as a medium to form colored complex Cu (I) -neocuproine chelate that was measured at 454 nm. The optimized FIA order was able to estimate of CPL. with a throughput 48 sample. h-1, flow rate 1.4 mL/min was used distilled water as a carrier, 51.02 L analyte volume (50 g. ml-1 CPL) with acetate buffer (0.1 M sodium acetate and 0.1 M acetic acid), 49.06 L Neocuproine (2x10-3M), 43.175 L Cu (II) nitrate.3H2O (8x10-3M) for L1, L2 and L3, respectively. Open valve model for sample inject and chemicals that used in the work. Calibration curves of absorbance against concentration sign of Beer, s law is submitted to within the concentrations scope of 1-80& 3-120. mL-1 of captopril with detection limits 1.5x10-1, 3.1x10-2 g. ml-1 and quantification limits, 5x10-1, 1.03x10-2 g/mL of captopril for batch and CFIA systems, respectively. a correlation coefficient (r) were 0.9960, 0.9981 and percentage linearity (r2 %) were 99.60 %, 99.81 %, repeatability (RSD %) (n=7) were 0.112 and 0.26 for estimation of captopril with concentration 30& 70 g. mL-1. The suggested procedure carried out successfully for estimation of CPL. in pharmaceutical formulations and statistical analysis of the values comparing with results by United States Pharmacopoeia ( USP) were also reported.