Simultaneous estimation of risperidone, olanzapine and quetiapine and its degradation products by HPLC

Abstract

A rapid, specific reversed phase HPLC method has been developed for simultaneous determination of Risperidone, Olanzapine and Quetiapine. Drugs were subjected to stress conditions such as acidic, alkaline and oxidative hydrolysis (30% H₂O₂ v/v). Chromatographic separation of these pure drugs was carried out on Luna C18 (250*4.6, 5µm) with a 50:50 (v/v) mixture of 20mM ammonium acetate (pH adjusted to 6.7 ± 0.5 with ammonia or acetic acid) and acetonitrile as mobile phase. The flow rate was 1.0 mL min^-1 and the analysis was monitored at 235 nm by UV detection. The system and method precision was found to be less than 1% for Risperidone, Olanzapine and Quetiapine. The assay results were linear from 35 to 65 μg mL⁻¹ for Risperidone (R ² ≥ 0.991), Olanzapine (R ² ≥ 0.992) and Quetiapine (R ² ≥ 0.999). Method validated showed it to be specific, precise, robust and linear over the range of analysis. Separation was complete within 10 min.  Degradation studies revealed that degradation products do not interfere with the determination of drugs.