Spectrophotometric Method for the Estimation of Finasteride in Tablets

A spectrophotometric method was developed for estimating finasteride, a 5a-reductase inhibitor used to treat benign prostatic hyperplasia, in tablet formulations. The method involves a reaction with 0.2% w/v 3-methyl-2-benzthiazolinone hydrazone (MBTH) and 7% w/v ferric chloride solution, producing a green color with an absorption maximum at 446 nm. This method is precise, with a reproducibility of 98.8%, and follows Beer's law in the concentration range of 2 to 10 µg/ml. The method was tested on 20 tablets of finasteride, showing accurate and reproducible results, with no interference from excipients in the tablets. The recovery studies confirmed the accuracy and precision of the method, making it suitable for routine quality control analysis of finasteride in bulk and dosage forms.