Estimation of Mirtazapine by HPTLC With Design of Experiments and it's Forced Degradation Study

Abstract

A sensitive, selective, precise, and stability-indicating (in accordance with ICH guidelines) high-performance thin-layer chromatography (HPTLC) method of analysis for mirtazapine was developed to resolve the drug response from that of its degradation products. In the study the robustness of HPTLC were decided by partial factorial design; analyze the three factors (saturation time, mobile phase ratio, band length ) in terms of in order which associated to the main factors and interaction effects; determine method development various parameters (precision, accuracy, linearity, limit of detection, limit of quantification, etc). TLC aluminum plates precoated with silica gel 60 F254 were used as the stationary phase. The solvent system consisted of methanol– chloroform, 7.5:2.5 (v/v). This system was found to give a compact spot for mirtazapine (RF value 0.52 ± 0.03). Mirtazapine was subjected to stress test conditions such as acid, alkali, neutral hydrolysis, oxidation, dry heat, and photodegradation. The spots for the product of degradation were well resolved from those of the drug. Densitometric analysis of drug was carried out in the absorbance mode at 293 nm. The linear regression data for the calibration plots showed good linear relationship with an r2 value of 0.994 in the concentration range 350–2150 ng/band. The result indicates that the drug was susceptible to degradation but to different extents under different conditions.