Simultaneous Determination of Mirtazapine and its Three Main Impurities by a High Performance Thin Layer Chromatography/Densitometry Method

Abstract

A quantitative densitometric high performance thin layer chromatography (HPTLC) method was developed for the simultaneous separation and quantification of Mirtazapine and its structurally related impurities. The three different impurities accounting for 3.3% were identified using TLC aluminium plates precoated with silica gel 60 F254 as the stationary phase. The mobile phase consisted of a saturated solution of toluene‐acetone‐methanol solution (6∶2∶2 v/v/v) and UV detection by absorbance reflectance at 285 nm facilitated the quantitative identification of the impurities along with the drug molecule. The minimum amount of Mirtazapine that could be authentically detected and quantified was 22.34 ng/spot and 74.47 ng/spot, respectively. The results of the present work showed that scanning densitometric HPTLC with online UV detection was simple, selective, accurate, and proved to be a valuable complementary method for quantitative evaluation of bulk drugs in the presence of their impurities.

Keywords:

• Mirtazapine
• HPTLC
• Densitometry
• Impurities