Highly sensitive spectrophotometric methods for the determination of olanzapine.

摘要

Highly sensitive and selective spectrophotometric methods (A and B) were developed for the detn. of micro amts. of olanzapine (OLZ). Method A (direct method) is based on the oxidn. of olanzapine with a known excess of iodine monochloride (ICl) in an acidic medium. Under the same condition, thymol blue was iodinated by unreacted ICl, and the absorbance of uniodinated thymol blue was measured at 536 nm. The decrease in ICl concn. is a measure of drug concn. In method B (indirect method), oxidn. of OLZ by a known excess of Ce(IV) in sulfuric acid medium followed by the reaction of unreacted Ce(IV) with leuco crystal violet (LCV) to crystal violet (CV), which is measured in an acetate buffer medium (pH 4.9) at 580 nm. These methods obey the Beer's law in the concn. range of 0.2-1.6 μg mL-1 (method A) and 0.1-1.4 μg mL-1 (method B). The developed procedures were successfully applied to the detn. of OLZ in pure and in dosage forms. The results exhibit no interference from the presence of excipients. The reliability of the methods was established by parallel detn. of OLZ against the ref. method. [on SciFinder(R)]