Extraction and liquid-chromatographic determination of amphotericin B in oil-water lecithin-based microemulsions

A method employing extraction then reproducible reversed-phase high-perform ance liquid chromatography (RPHPLC) with monitoring of the drug by absorban ce at 405 nm has been developed and validated for the determination of amph otericin B in oil-water lecithin-based microemulsions. The precision and ac curacy of the method are excellent (SD 2.4 % and 4.2 %, respectively). The established linearity range was 10-60 mu g mL(-1) (r(2) = 0.9967). The reco very of amphotericin B from spiked placebo was >90 % over the linear range. The extraction procedure was simple and the HPLC conditions were able to s eparate the drug from its degradation products and excipients. The method h as been used successfully for determining the amphotericin B content of mic roemulsions and for evaluating the chemical stability of amphotericin B-loa ded microemulsions.