development and validation of a rapid hplc method for simultaneous analysis of budesonide and its novel synthesized hemiesters in colon specific formulations

a simple and reliable reversed-phase high performance liquid chromatographic (hplc) method was developed, validated and applied for determination of budesonide and its novel synthesized hemiesters in colon specific formulations and dissolution media. the method was employed on a μ-bondapak c 18 column (250 mm × 4.6 mm, 5 µm) at ambient temperature. the mobile phase consisted of acetonitrile: monobasic potassium phosphate containing orthophosphoric acid (55:45, ph 3.2) at a flow rate of 1 ml/min. the uv detection wavelength was set at 244 nm and 50 µl of sample was injected into the hplc system. dexamethasone was used as the internal standard. the retention times for internal standard and budesonide were 4.5 and 7.2 min, respectively. the method was linear in the concentration range of 1-20 µg/ml of budesonide (r 2 >0.999). limit of detection and limit of quantitation were 0.05 and 0.5 µg/ml, respectively. the method presented the requisite accuracy, selectivity, sensitivity and precision and showed good resolution for separation of the drug and related derivatives in the presence of excipients. the proposed method was successfully used for analysis of the drug and its derivatives in dissolution media and oral colon specific formulations prepared in our laboratory with enough reproducibility.