Utilization of Ion-Associate Formation in Spectroscopic and Conductometric Determination of Mebeverine Hydrochloride in Pharmaceutical Formulations

Spectroscopic and conductometric determination of Mebeverine hydrochloride (MVH) with two ion-pairing reagents; Ammonium Reineckate (Amm.Rt) and Chromotrope 2R (C2R) has been described. The molar combining ratio reveals that (1:1) (drug: reagent) ion associates are formed by both reagents with MVH. The proposed conductometric procedure has been utilized for the determination of equilibrium constant of the reaction as well as other functions such as solubility product of the formed MVH ion associates. In addition, working upon the formerly obtained data operating differential conductivity methods (numerical first and second derivative) and Boltzmann nonlinear fitting was more adequate and systematic for data analysis compared to the conventional method. The described procedures allowed the determination of MVH within the range of 3-15 mg using both reagents. Moreover, the obtained precipitate has been spectroscopically characterized using IR and H-1-NMR. The proposed conductometric method was applied successively to pharmaceutical formulations containing MVH and the results obtained were favorably compared with those obtained using the official method.