抄録
Solubilities and initial dissolution rates of indomethacin polymorphs, pure α and γ forms, in water at various temperatures were determined, and from these parameters and temperatures, the heats of solution, ΔH2(soln), and heats of dissolution, ΔH2(diss), of these polymorphs were obtained. The activities of these polymorphs in water were calculated using the ideal solubility equation, and the activity coefficients were also calculated from these activities and mole fraction solubilities. The heats of solution, ΔH2(soln), of these polymorphs were evaluated using melting points, heats of fusion at the melting points, mole fraction solubilities and activation coefficients. Comparing ΔH2(soln) with ΔH*2(soln) or ΔH2(diss), it was suggested that ΔH2(soln) corresponded to ΔH2(diss) rather than to ΔH2(soln).
