Development and validation of stability indicating RP-HPLC and HPTLC for determination of Niclosamide in bulk and in synthetic mixture

Two simple, specific, sensitive, accurate and precise stability indicating methods were described for quantitative determination of the anthelmintics drug Niclosamide. The first method was high performance liquid chromatographic with the use of a reversed phase hibar(R) C-18 column (250 mm x 4.66 mm, 5 mu m) and mobile phase of methanol: 1 mM ammonium phosphate buffer (85:15 v/v) at a flow rate of 1.2 mL/min. The retention time of drug was found to be 6.45 +/- 0.02 min. Quantification of drug was achieved with diode array detection (DAD) at 332 nm. Linear calibration curve was obtained in concentration range 0.01-100 mu g/mL with r(2) value of 0.999. The limit of detection and limit of quantification were found to be 0.048 mu g/mL and 0.01 mu g/ml respectively. The second method involved a high performance thin layer liquid chromatographic. Chromatographic separation was carried out with precoated silica gel G60 F254 aluminum sheets using toluene:ethyl acetate (7:3% v/v) as a mobile phase. Linearity of proposed method was found to be 200-700 ng/band at 332 nm with retention factor of 0.59 and r(2) value of 0.998. The limit of detection and limit of quantification were found to be 36.21 ng/band and 109.7 ng/band respectively. Both the developed methods were successfully validated as per International Conference on Harmonization guideline (ICH). Niclosamide was subjected to different stress conditions. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time. Stress samples were successfully assayed by developed high performance liquid chromatographic and high performance thin layer liquid chromatographic method. Statistically analysis proves that there were no statistical significant differences between two developed methods. (C) 2015 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).