Green Chemistry Approach for Determination of H2-receptor Antagonists in Their Pharmaceutical Dosage Forms with an Optical Probe

An environmentally safe, sensitive and simple spectrophotometric method has been developed for determination of H₂-receptor antagonists: cimetidine (CIM), famotidine (FAM), nizatidine (NIZ), and ranitidine hydrochloride (RAN). The method was depend on the reaction of the studied drugs with N-bromosuccinimide (NBS), a green reagent, the excess NBS was determined by its reaction with metanil yellow (MY) and measuring the absorbance at 530 nm. The absorption intensity was correlated with drug concentrations. By using of the optimum conditions, linear calibration curves with good correlation coefficients (0.9991–0.9998) were found between the measured absorbance values and the corresponding drugs concentrations in the range of 2.0–25 μg mL⁻¹. Limits of detection were in the range 0.42–0.67 μg mL⁻¹. The proposed method was successfully applied for the analysis of H2RAs in their pharmaceutical dosage forms and the results were comparable with that obtained by the official methods.