High Performance Liquid Chromatographic Assay of Terbutaline for Preformulation Studies

Abstract

A reversed phase, stability indicating high performance liquid chromatographic (HPLC) assay was developed for the evaluation of terbutaline (TL) as a potential candidate for transdermal drug delivery. TL was quantitated in the permeation diffusate and human skin extract samples. The isocratic mobile phase was 30 % acetonitrile in pH 5.6 phosphate buffer. The effluent was monitored at 225 nm. Propranolol (PP, 2.5 μ/ml) was used as the internal standard. Baseline separation of TL and PP was attained with a cyano column. The linear range for the calibration curve was established at 5–15 μg/ml. The assay was reproducible with low inter-day and intra-day variation of the slopes of the calibration curves (3.5 and 4.2% for diffusate samples and 5 and 5.5% for the human skin extract samples respectively). The lowest detectable quantity was 0.1 μg/ml with a signal noise ratio of 4. The application of the assay in various preformulation studies was demonstrated.