Spectrophotometric, atomic absorption and conductometric analysis of tramadol hydrochloride

Abstract

Six simple and sensitive spectroscopic and conductometric procedures (A-F) were developed for the determination of tramadol hydrochloride. Method A,B and C are based on the reaction of cobalt (II) thiocyanate with tramadol to form stable ternary complex, which could be measured by spectrophotometric (method A), atomic absorption (method B) or conductometric (method C) procedures. Method (D and E) depended on the reaction of molybdenum thiocyanate with tramadol to form stable ternary complex, measured by spectrophotometric means (method D), or by atomic absorption procedures (method E), while method F depends on the formation of an ion pair complex between the studied drug and bromothymol blue which is extractable into methylene chloride, Tramadol hydrochloride could be assayed in the range of 80-560 ?g ml-1, 40-220 ?g ml-1, 1-15 mg, 2.5-22.5 ?g ml-1, 1.25-11.25 ?g ml-1 and 5-22 ?g ml-1 using methods A,B,C,D,E and F respectively. Various experimental conditions were studied. The results obtained showed good recoveries. The proposed procedures were applied successfully to the analysis of tramadol in its pharmaceutical preparations and the results were favorably comparable with the official method.