Use of sodium tetraphenylborate reagent for conductometric titration of Amlodipine Besylate in pure and pharmaceutical forms

Abstract

Simple, accurate and reliable conductometric method for the quantitative determination of Amlodipine Besylate (AML) in pure form and pharmaceutical formulations using sodium tetraphenylborate (TPB) in aqueous solution at 20°C has been described. The method is based on the formation of ion association complex of cation coming from the cited drug with tetraphenylborate anion and the conductance of the solution is measured as a function of the volume of titrant. Many experimental conditions were evaluated. The described procedure allowed the determination of AML in double distilled water in the range of 0.200-1.000mM. The accuracy of the method is indicated by the excellent recovery 98.60-101.40%, and the precision is supported by the low relative standard deviation < 4.74 %. The method was further applied successively to pharmaceutical formulations with no interference from the excipients, the results obtained were compared statistically with those obtained by the official method and showed no significant differences regarding accuracy and precision.