Utility of N-bromosuccinimide as an Environmental-Friendly Reagent for Sensitive Determination of Olanzapine in Pharmaceuticals

One titrimetric and two spectrophotometric methods are described for the determination of olanzapine(OLP) in bulk drug and dosage forms. The methods use N-bromosuccinimide (NBS) and two-dyes, namelyquinoline yellow and metanil yellow, as reagents. In titrimetry, an acidified solution of OLP was titrateddirectly with NBS using methyl orange as indicator. Spectrophotometry involves the addition of a knownexcess of NBS to OLP in acid medium followed by determination of unreacted NBS by reacting with afixed amount of either quinoline yellow and measuring the absorbance at 410 nm (method A) or metanilyellow and measuring the absorbance at 530 nm (method B). Titrimetric method is applicable over a rangeof 1-10 mg of OLP, and the reaction stoichiometry is found to be 1:6 (OLP: NBS). In spectrophotometry,Beer’s law was obeyed in the concentration ranges of 0.1–1.2 and 0.1–1.5 μg ml–1 OLP for method A andmethod B, respectively. The molar absorptivity, Sandell sensitivity, limits of detection and quantificationare also reported for both the spectrophotometric methods. The proposed methods were appliedsuccessfully to the determination of OLP in tablets. The reliability and accuracy of the methods werefurther ascertained by recovery studies. A major advantage of the use of NBS is that the by-productsuccinimide can be easily recovered and recycled to NBS