Separation and determination of terbinafine and its four impurities of similar structure using simple RP-HPLC method

摘要

A novel reversed-phase HPLC method for the simultaneous determination of active component terbinafine, its one impurity 1-methylaminomethylnaphtalene and three degradation products, beta-terbinafine, Z-terbinafine and 4-methyl-terbinafine occurring in pharma-ceutical formulations after long-term stability tests, was developed and validated using propylparaben as an internal standard.The chromatographic separation was performed on a NUCLEOSIL 100-5-CN column, mobile phase for separation of all compounds consisted of a mixture of tetrahydrofurane, acetonitrile and citrate buffer pH 4.50 (10:20:70, v/v/v).The analysis time was less than 32 min at flow-rate of 0.8 ml min~(-1).UV detection was performed at 226 nm.The method was validated and system suitability parameters were investigated.Method robustness and short-term standard solution stability were verified.Limits of detection for terbinafine degradation products/impurity were from 0.023 to 0.098 mugml~(-1), limits of quantitation were from 0.078 to 0.327 mugml~(-1).The method was applicable for routine determination of terbinafine and all its found impurities of similar structure with sufficient selectivity, precision and accuracy.