Effects of cyclodextrins on chlorpromazine-induced haemolysis and central nervous system responses.

Cyclodextrins (CyDs) protected the human erythrocytes from haemolysis induced with chlorpromazine (CPZ) in isotonic solution, depending upon the magnitude of the stability constant of CPZ-CyD complexes (beta-greater than-gamma-greater than alpha-CyD). From the observations of CPZ uptake into erythrocytes and changes in surface activity of CPZ, the protective effects of CyDs in vitro appeared to be due to the decrease in effective haemolytic concentration of CPZ through inclusion complex formation rather than the direct interaction of CyDs with the erythrocyte membrane. The effect of beta-CyD on some central nervous system (c.n.s.) actions of CPZ in rats was also investigated to see if there were any advantages in the use of beta-CyD complexes given by injection. The results suggest that beta-CyD does not after the time-course or magnitude of the effects of CPZ on the c.n.s.