Development and validation of a spectrophotometric method for estimation of letrozole in bulk and pharmaceutical formulation.

A simple, sensitive and accurate UV spectrophotometric method has been developed for the determination of letrozole, a new aromatase inhibitor, in raw material and tablets. The drug shows maximum absorption at 238 nm. Beer's law was obeyed in the concentration range 2-20 microg/mL for the drug. Results were validated statistically according to ICH guidelines. Validation of the method yielded good results concerning range, linearity, precision and accuracy. It was found that the excipients present in the commercial formulation did not interfere with the method.