Development of a validated liquid chromatography–diode array detection method for simultaneous determination of olanzapine and fluoxetine in their combined formulation: Application to greenness assessment

Abstract

AbstractOlanzapine and fluoxetine hydrochloride are two promising drugs recommended for use in combination to treat bipolar psychotic disorders. In the present study, a green liquid chromatographic method is reported for simultaneous quantification of the said combination by employing analytical eco‐scale principles. The penalty point scoring process revealed an excellent greener nature of the current method than the reported methods. Chromatographic separation was achieved on a C‐18 column employing methanol and phosphate buffer of pH 3.5 as the mobile phase at a flow rate of 1.0 mL/min and detected at 227 nm. Both the analytes were separated with resolution > 2.0. Method validation revealed apt linearity (r2 = 0.999), accuracy (> 99%), and precision (overall % relative standard deviation < 1%) for quantification of the analytes. The limits of detection and quantitation were compliant as per study intent. Further, a systematized chemometrics approach using risk assessment and design of experiments revealed the influence of critical method variables on the method's robustness. Optimum system suitability and assay results confirmed selectivity and revealed the specific nature of the method. Overall, a robust and greener analytical method is established for the routine simultaneous quantification of the two antipsychotics in their combined tablet dosage form.