DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR THE ESTIMATION OF DOXOFYLLINE AND TERBUTALINE IN PURE AND IN ITS FORMULATION

A new simple, rapid, and sensitive reversed-phase liquid chromatographic method was developed for the estimation of doxofylline and terbutaline in the tablet dosage form. The chromatographic separation was achieved on ODS C₁₈column (150 × 4.6 mm, 5 µm) at ambient temperature and effluent monitored at 257 nm. The mobile phase consists of ammonium acetate buffer (pH adjusted to 3 with o-phosphoric acid) and acetonitrile in the ratio of 50:50 v/v. The flow rate was maintained at 1 ml/min. The method was validated concerning linearity, precision, accuracy, ruggedness, limit of detection, limit of quantification and robustness. The assay methods were found to be linear from 16-96 µg/ml for doxofylline and 0.2-1.2 µg/ml for terbutaline. All validation parameters were within the acceptable range. The mean recovery was 99.35 and 99.25 for doxofylline and terbutaline respectively. The % RSD value was found to be less than 2. The limit of detection and limit of quantification for doxofylline and terbutaline were found to be 0.06 μg/ml and 0.024 μg/ml and 0.21μg/ml and 0.079 μg/ml respectively. The result of the study showed that the proposed RP-HPLC method for the simultaneous estimation of doxofylline and terbutaline in the tablet dosage form is simple, accurate, sensitive, precise, specific and rapid which is useful for routine analysis of doxofylline and terbutaline in its formulations.