Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2004.79.81AlamS.M. MahbubulAkterM. Jamil RezaM. Nadim IsratFatima AhmedFiroj ShilpiJ.A. 1200471The study of drug-drug interaction between Ciprofloxacin and Captopril at binding sites of Bovine Serum Albumin (BSA) was studied by equilibrium dialysis (ED) method. During concurrent administration of these drugs, Captopril (an ACE inhibitor) and Ciprofloxacin HCl (a broad spectrum antibacterial drug) have been found to increase the free concentration of Captopril due to Ciprofloxacin causing reduced binding to BSA. The increment in free concentration of Captopril was more prominent in presence of site-II specific probe (diazepam) than in absence of same probe. When no probe and no Ciprofloxacin was added the free concentration of Captopril was only 5% whereas this release was 23% when Ciprofloxacin was added with an increasing concentration from 1 x10-5 to 12 x10-5 M. The increment of free concentration of Captopril was from 9.5% to 43% in presence of site-II specific probe upon the addition of Ciprofloxacin with an increasing concentration from 0x10-5 to 12 x10-5 M. During concurrent administration site-to-site displacement has taken place.]]>Brown, J.R.,19763521412144Jiunn, H.L., D.M. Cochetto and D.E. Duggan,198712402432Meloun, B., L. Moravec and V. Kostka,197558134137Sjoholm, I.,1980177677Brown, J.R.,19771977pp: 27-51pp: 27-51Rahman, M.H., K. Yamasak, Y.H. Shin, C.C. Lin and M. Otagiri,19931611691174Singlas, E.,19872nd Edn.,pp: 25-31pp: 25-31Singlas, E.,1987Chapter 1. 2nd Edn.,pp: 20-22pp: 20-22