STUDIES ON COPRECIPITATE OF ANORDRIN—PVP

The copreeipitate of anordrin (AD)—PVP was prepared by solvent method. The DSC (differential scanning calorimetry) revealed that AD did not have crystalline structure in copreeipitates of 1:7～1:9. X-ray diffraction spectrum of 1:8 coprecipitate (COPPT) showed no crystalline structure of AD. The dissolution rate of AD was about 38 times higher for 1:8 COPPT than pure AD. Activation energies determined by DTG (derivative thermogravimetry) were 182.8 and 133.4 kJ/mol, respectively, showing that the 1:8 COPPT is much more ' stable than pure AD in thermal degradation. The experimental results showed that antiimplantation effect of the 1:8 COPPT was much better than that of AD tablets: the number of implantation sites of mice administrated 1:8 COPPT (Smg/kg) was 0.2 (P<0.01) and that of mice administrated AD tablets (10.6 mg/kg) was 0.9 (P<0.05); effective dose of 1:8 COPPT was less than half of that of AD tablets.