Stability-Indicating RP-HPLC Method for the Simultaneous Estimation of Doxofylline and Terbutalinesulphate in Pharmaceutical Formulations.
An isocratic, stability-indicating, reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of doxofylline and terbutaline sulphate, used for the treatment of respiratory problems. The chromatographic separation was achieved on a Zorbax-SB Phenyl 250 × 4.6mm × 5 μm column with the mobile phase consisting of a mixture of 25 mM ammonium acetate (pH 5.0) : acetonitrile (85:15 %v/v) at a flow rate of 1.0 ml/min. The eluate was monitored at 274 nm using a PDA detector. Forced degradation studies were performed on the bulk sample of doxofylline and terbutaline sulphate using acid (0.1N HCl), base (0.1N NaOH), oxidation (10% hydrogen peroxide), photolytic, and thermal degradation conditions. Good resolution was observed between the degradants and analytes. Degradation products resulting from the stress studies did not interfere with the detection of doxofylline and terbutaline sulphate, thus the assay is stability-indicating. The method has the requisite accuracy, selectivity, sensitivity, and precision for the simultaneous estimation of doxofylline and terbutaline sulphate in bulk and pharmaceutical dosage forms. The limit of quantitation and limit of detection were found to be 1.16 μg/ml and 0.38 μg/ml for doxofylline, 2.08 μg/ml and 0.62 μg/ml for terbutaline sulphate, respectively.
Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, India.
Gananadhamu
G
Samanthula
Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, India.
Krishnaveni
K
Yadiki
Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, India.
Shantikumar
S
Saladi
United States Pharmacopeia - India Private Limited, Research and Development Laboratory, ICICI Knowledge Park, Turkapally, Shameerpet, Hyderabad, India.
Sreekanth
S
Gutala
United States Pharmacopeia - India Private Limited, Research and Development Laboratory, ICICI Knowledge Park, Turkapally, Shameerpet, Hyderabad, India.
K V
KV
Surendranath
Chromatography; Doxofylline; Method Development; Stability; Terbutaline sulfate; Validation