Analysis of low concentration sufentanil citrate/bupivacaine hydrochloride admixtures, using solid phase extraction...

A method has been developed for the quantitative determination of low concentrations of sufentanil citrate (1.0 microg/ml), in the presence of bupivacaine hydrochloride (0.125%), in the quality control of pharmaceutical preparations. The main problem in analysis of this combination is the low concentration of sufentanil citrate in the presence of relatively high concentrations of bupivacaine hydrochloride. This paper describes the validation of a HPLC method of sufentanil citrate in an admixture with bupivacaine hydrochloride using solid phase extraction (SPE). The optimized method shows good linearity, precision and accuracy. The limits of detection (0.09 microg/l) and quantification (0.29 microg/l) for sufentanil citrate are lower than the maximal accepted limits. This method is currently used in stability studies.