CRYSTALLINE PAMIDRONIC ACID DISODIUM SALT HYDRATE AND METHOD FOR PREPARING THE SAME

摘要

PURPOSE: A crystalline pamidronic acid disodium salt hydrate is provided, which has excellent storability and is easily processed to a preparation for oral administration. And a method for preparing thereof is also provided. CONSTITUTION: The crystalline pamidronic acid disodium salt hydrate has a water content of 17.0-20.0% and is a mixture form of pamidronic acid disodium salt trihydrate and pamidronic acid disodium salt tetrahydrate. The hydrate is represented by the following formula (1), wherein x is 3 or 4. The method comprises steps of: (i) neutralizing pamidronic acid and sodium hydroxide between pH 7.5-8.5; (ii) after filtering the produced insoluble material of the step (i), adding isopropanol to the filtrate to form a salt; (iii) after dissolving the obtained salt in water, leaving it at room temperature to crystallize it; (iv) cooling and filtering the crystallized solution of the step (iii) to obtain a crystal; and (v) drying the obtained crystal at a temperature of 75-85 deg.C under atmospheric pressure.