colorimetry.

For the estimation of tolterodine tartrate a new simple and accurate visible spectrophotometric method was developed. The proposed method was based on the formation of yellow-orange colored complex results from complete mixing of tolterodine tartrate, methyl orange and chloroform, which shows the maximum absorption at the wave length 417 nm. The linear relationship between the absorbance and the concentration of tolterodine tartrate was in the range of 20 – 120 µg/ml with a correlation coefficient = 0.997. This new method has offered a determination of tolterodine tartrate drug without any interference with excipients indirectly with a high accuracy for the analytical results. The method was found to be simple, economic, accurate and reproducible and can be used for routine analysis of tolterodine tartrate in bulk and in pharmaceutical formulation.