“…UV-Visible spectrophotometry is the technique of choice even today in the third world countries due to its low cost, ease of operation, high sensitivity, and simplicity of the instrumentation used for the technique. Several spectrophotometric methods based on the reaction of LBT with sodium nitroprusside and hydroxylamine hydrochloride [20], p-N,N-dimethylphenylenediamine hydrochloride [21], suprachen violet 3 B [21], diazotized 4-aminobenzene sulfonic acid [22], potassium permanganate [23], diazotized benzocaine in presence of trimethylamine or diazotized p-nitroaniline in the presence of sodium carbonate [24], and ferric 1, 10phenanthroline [25 ] have been developed to determine the concentration of LBT in bulk drug and pharmaceutical formulations effectively. Among these, only diazotized based method has been used to analyze LBT in biological samples [24].…”