ABSTRACT
This paper describes sensitive, accurate and precise spectrophotometric, TLC-spectrodensitometric and high performance liquid chromatographic [HPLC] methods for simultaneous determination of olanzapine and fluoxetine HCl. Two spectrophotometric methods were developed, namely; first derivative [D[1]] and derivative ratio [DD[1]] methods. The TLC method employed aluminum TLC plates precoated with silica gel GF[254] as the stationary phase and methanol: toluene:ammonia [7:3:0.1, by volume] as the mobile phase, where the chromatogram was scanned at 235 nm. The developed HPLC method used a reversed phase C18 column with isocratic elution. The mobile phase composed of phosphate buffer pH 4.0:acetonitrile:triethylamine [53:47:0.03, by volume] at flow rate of 1.0 mL min[-1]. Quantitation was achieved with UV detection at 235 nm. The methods were validated according to the International Conference on Harmonization [ICH] guidelines. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The developed methods were successfully applied for the determination of olanzapine and fluoxetine HCl in bulk powder and combined capsule dosage form