Validation of high-performance liquid chromatographic methods on two silica base-deactivated reversed phases for the determination of chloroprocaine and bupivacaine.

The separation of HPLC of basic drugs on silica-based reversed phases remains a major problem because of the interaction between the residual silanol groups of the silica and the amino function of the drug. This paper describes the validation of HPLC methods for the determination of two injectable solutions of basic drugs (two local anaesthetics, chloroprocaine and bupivacaine), with two commercial base-deactivated reversed phases. These columns improve the chromatographic performances without adding a blocking agent to the mobile phase. With a simple aqueous-organic mobile phase, these base-deactivated reversed phases give high theoretical plate numbers (N) and small tailing factors. The optimized methods show good linearity, precision (RSD < 2%) and accuracy (bias < 2% for dosage forms). The limits of detection and quantitation are lower than the maximal accepted limits for impurities. These methods are currently in routine use in stability studies.