Application of redox reactions for the determination of valganciclovir hydrochloride in pharmaceuticals

Abstract

Two simple, selective and sensitive spectrophotometric methods were developed and validated for the determination of valganciclovir hydrochloride (VLGH) in pure drug and tablets. The first method was based on the reduction of iron(III) to iron(II) by VLGH and subsequent formation of iron(III)-ferricyanide complex (Prussian blue) in acid medium which was measured at 730 nm (method A). In the second method (method B), permanganate was reduced by VLGH to bluish green manganate in alkaline medium and the absorbance was measured at 610 nm. The absorbance measured in each case was related to VLGH concentration. The experimental conditions were carefully studied and optimized. Beer's law was obeyed over the concentration ranges of 2.5-20.0 and 2.0-40.0 µg mL -1 for method A and method B, respectively, with corresponding molar absorptivity values of 1.28×10 4 and 6.88×10 3 L mol -1 cm -1 . The limits of detection (LOD) and quantification (LOQ) were 0.11 and 0.33 µg mL -1 (method A) and 0.21 and 0.64 µg mL -1 (method B). Within-day and between-day relative standard deviations (%RSD) at three different concentrations levels were < 2.4%, and the respective relative errors (%RE) were ≤ 3%. The proposed methods were successfully applied to the determination of VLGH in tablets, and the results confirmed that the proposed methods were equally precise and accurate as the official method.

Development of Potentiometric Method for In Situ Testing of Terbinafine HCl Dissolution Behavior Using Liquid Inner Contact Ion-Selective Electrode Membrane

“…TER is an official drug in British Pharmacopoeia 1 and United States Pharmacopoeia. 5 Several methods were described for TER determination in pharmaceutical formulations such as UV−spectrophotometric methods, [6][7][8] HPLC, 9,10 capillary zone electrophoresis, 11 voltammetry 12 and potentiometry. 13 Also, TER was determined in biological fluids by spectrofluormetry, 14 HPLC 15 and UPLC.…”

Spectrophotometric/Titrimetric Drug Analysis

“…These reactions involve a transfer of electrons between two species and a change in the oxidation number of species by gaining or losing an electron, generating a colored species. Many scientific published papers indicated oxidation-reduction reactions, that include; valganciclovir hydrochloride with iron (III) and KMnO 4 [30], amoxycillin, ampicillin, and cloxacillin with iodate [17], Olanzapine with N-Bromosuccinimide and Cerium (IV) sulfate [56], captopril with a mixture of KBrO 3 and KBr [57], to name a few. Table 3.…”

“…If we follow the international refereed journals that are concerned with publishing scientific research in the field of drug analysis, we will find that the majority of published research has used the spectrophotometric technique in analysis, directly or indirectly. To name a few, in the estimation of some anti-infective agents in pharmaceuticals, we will find that most of the published research about it used spectroscopic methods [21][22][23][24][25][26][27][28][29][30]. We also find that browsing through the majority of pharmaceutical analysis books finds that all of them give more space in that books to talk about spectrophotometric techniques and their various applications, especially in the field of drug analysis.…”