Development and validation of an HPTLC method for determination of olanzapine in formulations

A new, simple, and rapid HPTLC method was developed and validated for quantitative determination of olanzapine on silica gel 60F254 layers using methanol-ethyl acetate (8.0 + 2.0, v/v) as the mobile phase. Olanzapine was quantified by densitometric analysis at 285 nm. The method was found to give compact bands for the drug (Rf = 0.35 +/- 0.02). The linear regression analysis data for the calibration plots showed a good linear relationship with r2 = 0.9997 in the concentration range of 100-600 ng/band. The method was validated for precision, recovery, repeatability, and robustness as per the International Conference on Harmonization guidelines. The LOD was found to be 23.90 ng/band, and the LOQ was 91.04 ng/band. Statistical analysis of the data showed that the method is precise, accurate, reproducible, and selective for the analysis of olanzapine. The method was successfully used for the determination of equilibrium solubility and quantification of olanzapine as a bulk drug, in a commercially available preparation, and in in-house developed mucoadhesive microemulsion formulations and solution.