Determination of new antidepressants in pharmaceuticals by thin-layer chromatography with densitometry.

A new and simple TLC-densitometry method has been developed for the simultaneous separation of the two noradrenergic and specific serotonergic antidepressants mirtazapine and mianserine and validated for their determination in commercially available tablets. The method used TLC plates precoated with silica gel 60F254 as the stationary phase, and the mobile phase consisted of hexane-isopropanol-25% ammonia (70 + 25 + 5, v/v/v). Densitometric analysis was carried out in the absorbance mode at 280 nm. The method was validated in accordance with International Conference on Harmonization guidelines in terms of linearity, LOD, LOQ, precision, and accuracy. Calibration curves were linear (R2 > 0.9970) with respect to peak area in the concentration range of 500-2500 and 500-5000 ng/spot for mirtazapine and mianserine, respectively. The LODs were 20 and 35 ng/spot for mirtazapine and mianserine, respectively. The described method was successfully applied to the determination of mirtazapine and mianserine in their pharmaceutical formulations with recovery ranging from 99.83 to 101.20% of the labeled amount of the compounds. The proposed method can be used in routine QC of these drugs in pharmaceutical formulations.