Variability in polyene content and cellular toxicity among deoxycholate amphotericin B formulations

Study Objective. To evaluate the toxicity of amphotericin B deoxycholate formulations. Design. In vitro experiment. Setting. University research center. Material. Human mononuclear THP-1 cells. Intervention. The human mononuclear cells were exposed in vitro for 2 hours to the following deoxycholate formulations of amphotericin B, in 2.5- and 5-mu/ml concentrations: Apothecon, Pharmacia, Sigma, Gensia, Pharma-Tek, and VHA. Measurements and Main Results. Toxicity of the amphotericin B formulations were assessed by measuring interleukin (IL)-1beta expression in an in vitro model. Amphotericin B content was measured by enzyme-linked immunosorbent assay (ELlSA), and amphotericin A and B contents were assessed by spectrophotometry. Endotoxin contamination was evaluated in all reagents. Expression of IL-1beta from Sigma, Pharmacia, and Pharma-Tek formulations was increased approximately 250%, 50%, and 25%, respectively, compared with amphotericin A. Amphotericin B content of Sigma, Pharmacia, Pharma-Tek, and Gensia formulations, as measured by ELISA, was increased approximately 450%, 200%, 200%, and 100%, respectively, compared with Apothecon. This variation could not be explained by differences in amphotericin A or B content as measured by spectrophotometry. Conclusion. Amphotericin B is obtained from a fermentation plant and manufactured as a pharmaceutical at different facilities. Both previous clinical observations and the current in vitro evaluation revealed significant differences among the formulations. Likely, other polyenes or pyrogenic toxins in differing amounts are in these formulations, thus explaining the variability in toxicity observed among the formulations.