Spectrophotometric methods for the determination of some diuretics using 3-methyl-2-benzothiazolinone hydrazone

Abstract

3-Methyl-2-benzothiazolinone hydrazone (MBTH) reagent in conjunction with various oxidising agents was found to be useful for the determination of eight widely used diuretics in pure and dosage forms. Of the eight diuretics, amiloride HCl, bumetanide and frusemide react with MBTH without any preliminary treatment, whereas the thiazide diuretics (benzthiazide, hydrochlorothiazide, hydroflumethiazide, polythiazide and trichlormethiazide) react only after release of the masked amino group through alkaline hydrolysis. Ce^IV, Fe^III and IO₄^– were found to be suitable oxidising agents for these procedures. The sensitivity of these methods is superior to that of many previously reported methods. The results compare well with the reference methods for these drugs.