A new quantitative densitometric HPTLC method has been developed for analysis and determination of the stability of anastrozole, both in the bulk material and in formulations. The method employed silica gel thin-layer chromatography (TLC) plates with fluorescent indicator, instrumental band-wise application of samples and standards, development with toluene-acetone-ammonia 6:4:0.3 (
) as mobile phase, and UV absorption/reflectance scanning with densitometric detection at 200 nm. The applicability of the method has been evaluated by analyzing a non-steroidal anti cancer tablet formulation containing anastrozole in specified amounts (as per label claim). Linearity, accuracy, precision, limit of detection, and limit of quantification were validated. Recovery of anastrozole from 1-mg tablet formulations ranged from 98.9 to 101.5%. Intraday and inter-day precision were 1.34% and 1.59% respectively. The limits of detection and quantification were 70.52 and 213.68 ng per band. The correlation coefficient for the anastrozole calibration plot was 0.9983 ± 0.0016 over the range of 500–1500 ng with regard to peak area. Stability-indicating studies suggested the drug does not undergo degradation under acidic or oxidizing conditions but alkaline conditions facilitated degradation, as was evident from the additional peaks observed. As the method could effectively separate the drug from its degradation products, it can be used as a stability indicating method and is thus suitable for routine quality-control analysis.
, Crit. Rev. Oncol. Hematol.