Conductometric Determination of Certain Pharmacological Drugs Using Silver and Bismuth

Two simple, rapid and accurate conductometric methods were developed for determination of losartan potassium, pantoprazole sodium, sumatriptan succinate, rabeprazole sodium and lomefloxacine HCl in pure form as well as in their pharmaceutical formulations. The proposed methods based on using two different precipitating agents for conductometric determination of the cited drugs. Method (A) based on reaction of losartan potassium, pantoprazole sodium, sumatriptan succinate and rabeprazole sodium with silver nitrate forming a white precipitate. Method (B) based on reaction of lomefloxacine HCl, pantoprazole sodium and sumatriptan succinate with bismuth tetraiodide, forming an orange red precipitate. Different factors affecting the reaction as concentration of both silver nitrate and bismuth tetraiodide, type of solvents used and also formation of the bismuth tetraiodide were carefully studied to obtain the best results. The described procedures allowed the determination of the studied drugs in the range of 5-15mg/50 mL for (method A) and 0.5-10mg/50mL for (method B). The proposed methods were validated and successfully applied for the determination of the studied drugs in pure form and in their pharmaceutical preparations. The obtained results were statistically compared with reference methods and no significant differences were found.