PHYSICOCHEMICAL PROPERTIES OF AMORPHOUS URSODEOXYCHOLIC ACID OBTAINEDBY GRINDING

The crystallinity and disorder parameters of intact and ground ursodeo xycholic acid were determined by the X-ray diffraction method based on Ruland's theory. An increase in grinding time caused a decrease in cr ystallinity, while the disorder parameters were independent of the gri nding time. Dissolution rates were measured for ursodeoxycholic acid w ith different crystallinities, and the recrystallization behavior of t he amorphous samples was investigated during storage in a vapor of wat er, n-hexane, n-octane and n-decane. The amorphous ursodeoxycholic aci d showed enhanced dissolution in ethanol, and was stable only under dr y conditions.