Development and Validation of a Simple Stability-Indicating TLC Method for the Determination of Levamisole in Pharmaceutical Tablet Formulation

A simple, selective, precise, and stability-indicating thin-layer chromatographic (TLC) method has been established and validated for analysis of levamisole (LEV) in pharmaceutical dosage. Normal phase precoated aluminum TLC silica gel 60F(254) plates were used as stationary phase and MeOH-toluene-chloroform (14:36:50 v/v/v) was used as mobile phase to determine LEV in pharmaceutical ingredients. The system was found to give compact spot for LEV (R(F) = 0.30). Determination was performed in absorbance mode at 223 nm. Regression analysis data for the calibration plots indicated good linear relationships between response and concentration over the range 60-2000 ng per spot and 0.998 correlation coefficient. The slope and intercept of the calibration plot were 4.946 and 267.6, respectively. The recovery of 88.44-102.57% with 2.02% inter-day and 1.91% intra-day relative standard deviations (RSDs) shows the validity of the method. Further, the limit of detection (LOD) and the limit of quantification (LOQ) were 2.2 and 7.5 ng per spot, respectively. For the stability study of LEV, it was subjected to acid, base, hydrogen peroxide, heat, and photodegradation (UV) conditions. Statistical analysis proved the method was repeatable, selective, and accurate for estimation of levamisole. The proposed method can be successfully used to determine the drug content of the pharmaceutical formulation.