Validated HPLC and HPTLC Methods for the Determination of Agomelatine in Bulk and Tablets

The present study represents validated simple, rapid and reliable chromatographic methods for analysis of the antidepressant drug agomelatine (AGO) in bulk powder and tablets.Method I involved application of RP-HPLC with diode array detection where Agilent Zorbax Eclipse-C18 column (4.6 × 150 mm, 5 μm) was used as stationary phase at ambient temperature (25±5).The mobile phase was composed of phosphate buffer (0.05 M, pH 3) and acetonitrile in the ratio 60:40 (v/v) and was pumped isocratically at 1 mL/min.In method II, HPTLC plates (20 × 10 cm, aluminum plates with 200-μm thickness precoated with silica gel 60 F254) was used as stationary phase with mobile phase composed of chloroform: methanol (9.3: 0.7, v/v).Detection was carried out at 230 nm in both methods.The structurally related melatonin was used as internal standard (IS) in both methods.The developed methods were validated according to International Council for Harmonization (ICH) guidelines with respect to linearity, ranges, accuracy, precision, robustness and limits of detection and quantitation.Linearity ranges were 0.5-3 μg/mL and 25-200 ng/spot in method I and method II respectively.Limits of detection and quantitation were 0.081 and 0.25 μg/mL for method I and 4.65 and 14.11 ng/spot for method II, respectively.Intra and interday precision were verified by the RSD% values which were less than 2%.The methods were implemented for assay of AGO tablet dosage form with no observable interferences.