A HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY FOR AMPHOTERICIN-B INA HYDROPHILIC COLLOIDAL PASTE BASE

A stability-indicating high-performance liquid-chromatographic (HPLC) assay has been developed for amphotericin B (AmB) in a paste, containi ng AmB, tobramycin (or gentamicin) sulphate, colistin sulphate, liquid paraffin and Orabase(R). Extraction of AmB was performed by partition ing the antibiotic between N,N-dimethylformamide (DMF) and cyclohexane , which led to precipitation of the polymeric materials and extraction of the liquid paraffin into the cyclohexane and AmB into the DMF. Ana lysis by HPLC of the latter layer gave a linear relationship between c oncentration and peak area response for the AmB over the range 5.0 x 1 0(-4) to 7.5 x 10(-3)% (w/v) (r = 0.9995) with a relative standard dev iation of +/- 1.46% (n = 8). The efficiency of extraction was 100.6 +/ - 2.4% (n = 5). (C) 1998 Elsevier Science B.V. All rights reserved.