The derivative spectrophotometric and IP-RP-HPLC determination of the Lometazid (R) tablets

In this paper the second-derivative spectrophotometric and ion-pair reverse d-phase high performance liquid chromatographic methods for the simultaneou s determination of some diuretic ingredients are described. Optimal conditi ons of both techniques for the quantitative analysis of the two-component d iuretic mixture of the Lometazid((R)) tablets were settled. The second-deri vative order of the spectra in sodium hydroxide with the wavelength modulat ion was used. For the determination of amiloride hydrochloride the 'zero-cr ossing' technique was applied, but for methyclothiazide the peak amplitude had to be corrected. In the ion-pair RP-HPLC technique tetrabutylammonium h ydroxide was applied as an ion-pairing agent using acetonitrile-phosphate b uffer (45:55 v/v) as a mobile phase. The validation was done of both propos ed methods, (C) 2000 Elsevier Science B.V. All rights reserved.