Extractive method development and validation of tulobuterol in api and its pharmaceutical dosage forms by spectrophotometry

Abstract

A simple, accurate, sensitive and reproducible visible spectrophotometric method has been developed for the determination of Tulobuterol (TLB) in bulk and also in its pharmaceutical dosage formulations. The proposed method was based on complexation of the drug with Bromo Cresol Green (BCG) extracted with chloroform showing absorbance maxima at 624 nm respectively. Beer's law is obeyed over a concentration range of 0.1-0.8g/mL. The respective linear regression equation being Y (0.0309) =1.065x +0.0396 for TLB. Results of analysis for the method established, was validated statistically and also by recovery studies. The color was stable for about 1 hour. The apparent molar absorptivity and Sandells Sensitivity values are 0.43x10 ⁴ L ^mol-1 cm ^-1 and 0.7674gcm ^-2 respectively. The assay and recovery studies were found to be 101.43% and coefficient correlation(r) was found to be0.994.The different experimental parameters effecting the development and stability were studied carefully and optimized. No interference was observed in the presence of common pharmaceutical excipients. The validity of the methods was tested by analyzing the drug in its pharmaceutical preparations. Good recoveries were also obtained. The developed method employed was successful for the determination of TLB in various pharmaceutical preparations.