AN EXPERIMENTAL-STUDY OF THE STABILITY OF CHOLESTEROL IN INORGANIC ELECTROLYTE AND BILE-SALT SOLUTIONS

The stability of cholesterol microcrystals in solutions of different pH values and different inorganic electrolyte and bile salt concentrations is experimentally analyzed using spectrophotometric techniques. The method employed allows a study of the aggregation kinetics of cholesterol suspensions. The zeta potentials characterizing the cholesterol/solution interface are computed from electrophoretic mobility data, a good correlation being found between changes in the electrical properties of the interface and variations in the stability of the suspensions. The latter are less stable the closer the pH to the isoelectric point, and the higher the concentrations of NaCl, CaCl2, or sodium deoxycholate. A very small effect is found on both mobility and stability of the suspensions when the concentration of sodium cholate is changed. © 1991.