| Abstract: | Abstract Difference (ΔA) and difference first- (ΔD1) and second- (ΔD2) derivative spectrophotometric methods are described for the assay and quality control of anafranil, a powerful antidepressant, in pharmaceutical formulations. The procedures are based upon the measurement of ΔA, ΔD1 and ΔD2 of anafranil in alkaline solutions against their acidic solutions as blanks. Interferences of the excipients and diluents or irrelevant absorptions are nullified. Calibration graphs of ΔA, ΔD1 and ΔD2 versus the concentration of the drug showed linear relationships up to 10 μg/ml, with correlation coefficients ranging from 0.9998 to 0.9999. Detection limits at p = 0.01 level of significance were calculated to be 0.060 (ΔA), 0.056 (ΔD1) and 0.063 (ΔD2) μg/ml. The limits of quantification were 0.45 (ΔA), 0.36 (ΔD1) and 0.81 (ΔD2) μg/ml. The procedures have been successfully applied to the determination of anafranil in synthetic samples and in commercial pills and injections for this drug with high reliability and repeatability. |
