engleski

NEW KINETIC METHOD FOR DETERMINATION OF N-ACETYL-L-CYSTEINE IN PHARMACEUTICAL FORMULATIONS

N-acetyl-L-cysteine (NAC) is a synthetic aminothiol antioxidant that has been in clinical use for more than 40 years, primarily as a mucolytic agent and in the management of paracetamol (acetaminophen) poisoning. There is a need for a new, robust, inexpensive, and rapid method of determination of NAC in pharmaceutical formulations, in order to assure proper quality control (QC). Novel flow-injection spectrophotometric method for the determination of NAC has been developed and validated. MATERIALS AND METHODS. The proposed method is based on the reduction of Cu(II)-neocuproine reagent to Cu(I)-neocuproine with the analyte, in a Britton-Robinson buffer solution (pH = 3.0). The non-steady state absorbance of the formed yellow Cu(I)-neocuproine complex is measured at 458 nm. A linear calibration curve is established in a concentration range of 6×10−7 to 4×10−5 mol L−1 NAC with regression equation y = 3.89´103 –0, 0015 (R2 = 0.9996) (n = 9) and detection limit of 9.4×10−8. The proposed method is simple, rapid, sensitive and reproducible (RSD 0.9%, n = 100). In addition, proposed method is sensitive enough to enable determination of near nanomole amounts of the NAC without expensive instruments with the analytical frequency of 120 h−1.

kinetic methods of determination; N-acetyl-L-cysteine; pharmaceutical formulations

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