Determination of Moxonidine and Its Impurities by Thin-Layer Chromatography

Abstract

A thin-layer chromatographic method for simultaneous determination of moxonidine and its four impurities was developed and validated. Separation of the examined compounds was performed on chromatographic plates precoated with silica gel 60 F₂₅₄ and using methanol–toluene–dichloroethane–ammonia 2:3:3:0.1 (v/v/v/v) as mobile phase. Ascending development mode was performed in the twin-trough chromatographic chamber, which was presaturated with mobile phase vapors for 15 min. The developed chromatographic plates were dried in air and densitometrically scanned at the wavelengths of 260 and 280 nm. Regression coefficients (r ≥ 0.998), recovery (90.10–107.63%), limit of quantification of impurities (20 ng band⁻¹ equivalent to the 0.12% impurity level), and robustness were validated and found satisfactory. The developed method is well suited for quantitative analysis and purity control of moxonidine in its dosage forms.

Keywords:

• impurities
• method validation
• moxonidine
• pharmaceuticals
• quantitation
• TLC