Development and Validation of a Stability-Indicating HPTLC Method for the Determination of Mirtazapine as Bulk Drug and in Pharmaceutical Formulation

摘要

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. TLC aluminum plates precoated with silica gel 60 F_(254) were used as the stationary phase. The solvent system consisted of methanoi-chloroform, 9:1 (v/v). This system was found to give a compact spot for mirtazapine (R_F value 0.56 +- 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 294 nm. The linear regression data for the calibration plots showed good linear relationship with an r~2 value of 0.994 in the concentration range 400-2000 ng/band. The result Indicates that the drug was susceptible to degradation but to different extents under different conditions.