Spectroscopic methods for the simultaneous estimation of theophylline and furosemide

The simple, sensitive and specific U.V. spectrophotometric methods were developed for simultaneous determination of theophylline (THE) and furosemide (FUR) in synthetic mixture. Spectrophotometric studies were carried out using double beam JASCO U.V. spectrophotometer with methanol as solvent. The present work includes two methods: method A- simultaneous equation method and method B-absorbance ratio method. Wavelength selected are 272 nm for THE and 275 nm for FUR respectively. In both the methods linearity were observed in the concentration range of 5-30 µg/ml and 5-35 µg/ml for THE and FUR, with good correlation coefficient 0.999 and 0.9988 respectively. Method B involved formation of absorbance equation at isobestic point (251 nm). THE and FUR are used for the treatment of asthma and congestive heart failure. Both methods showed high sensitivity with reproducibility in result