engleski

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

INTRODUCTION. 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). Patient safety during therapy, on the other hand, is indirectly linked with proper QC of the medication. 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. The three-line manifold with one reaction coil was used. Optimization of manifold parameters and experimental conditions were carried out by means of univariate method. RESULTS. 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. CONCLUSION. The proposed method can be applied for the determination of NAC in pharmaceutical preparations. Therefore, it could be useful for QC of NAC-containing medications, indirectly improving patient safety during therapy (reducing risk of under or over- dosage).

N-Acetylcysteine; Kinetic spectrophotometry; pharmaceutical formulations

nije evidentirano