Abstract

A simple, rapid and reliable titration procedure for mercurimetric assay of ranitidine hydrochloride (RHCl) in the tablet formulations is proposed by measuring the chloride content of its hydrochloride salt. The amount of RHCl in the sample solution was determined by measuring its volume required for titration with the known amount of mercury(II) nitrate, using mercury(II) thiocyanate-iron(III) nitrate indicator system. The procedure was initially set up for determination of RHCl in the range 3.5087 to 7.0174 g/lit by using standard 0.01 to 0.02 M RHCl solutions. The reaction stoichiometry was found to be 2:1 [RHCl: Hg(NO3)2]. Statistical information obtained by using experimental data illustrates that the procedure is accurate and precise. The procedure was further implemented for the assay of RHCl in the tablet formulations. The average accuracy was found to be in agreement with claimed by the manufacturer. Excipients used in tablet formulations did not interfere as shown by the recovery experiment using standard addition method. In conclusion, the proposed procedure is found to be excellent for titrimetric assay of RHCl in acidic homogenous solution and it is free from the titration errors; those commonly encountered by co-precipitation in argentimetric assay of RHCl.