Development and Validation of an HPLC Method for Impurity Profiling in Terbutaline Sulfate Oral Syrup

Terbutaline sulfate is a pediatric β2-adrenergic agonist that acts as a bronchodilator by stimulating β2-adrenoceptors in bronchial smooth muscle. A novel and reliable high-performance liquid chromatography method was developed to identify process- and degradation-related impurities in terbutaline sulfate oral syrup. The separation was achieved using an Inertsil ODS-3 column (250 × 4.6 mm, 5 μm) maintained at 30°C, with a mobile phase composed of buffer and acetonitrile delivered at a flow rate of 1.0 mL/min under a linear gradient elution mode. The injection volume and sample concentration were set at 40 μL and 500 μg/mL, respectively. The drug and its impurities demonstrated good linearity, with determination coefficients greater than 0.999. Recovery rates at all levels ranged from 95% to 105%. Forced degradation studies were conducted under acidic, alkaline, oxidative, thermal and photolytic forced degradation conditions. Under photolytic forced degradation, Imp-B and three furfural-related degradation impurities were formed. The validated stability-indicating HPLC method, which has been verified in accordance with International Conference on Harmonisation guidelines, is suitable for both stability studies and routine quality control.