Abdel-Fattah, LailaEl-Kosasy, AmiraAbdel-Aziz, LobnaGaied, Mariam2014-06-072014-06-072013-05Abdel-Fattah Laila, El-Kosasy Amira, Abdel-Aziz Lobna, Gaied Mariam. Interaction of Losartan potassium with the micelles of Triton X 100. Journal of Applied Pharmaceutical Science. 2013 May; 3(4 suppl_1): s38-s43.http://imsear.searo.who.int/handle/123456789/151806This study is an investigation of the physicochemical interaction of Losartan potassium (LST K), an angiotensin-II receptor (type AT1) antagonist, with micelles of triton X, a nonionic surfactant. The effect of micelles on the spectral properties of LSTK was monitored on at pH 7.4 and at room temperature. The spectrum of LST K showed gradual and progressive bathochromic and hypochromic shift in presence of increasing concentrations of triton X 100. The binding constant Kb of LST K to triton X 100 micelles was calculated using the differential absorbance at λ = 225 nm& was found to be 4.13 ± 0.35 ×105 mol-1 L. By using pseudo-phase model, the partition coefficient between the bulk water and Triton X 100 micelles, Kx, was calculated from both differential absorbance Δ A225, Kx = 2.26 ±0.12 x105 mol-1 L. The binding of LST K to Triton X 100 micelles implied a shift in drug acidity constant (Δ pKa = 0.8).enLosartan potassiumTriton X 100micellespartition coefficient and bindingArticle