Preformulation investigation of the novel proton pump inhibitor lansoprazole

Some technologically important physicochemical properties of lansoprazole w ere investigated. This compound is very unstable, especially in aqueous sol utions with low pH. It has one acidic and two basic dissociation constants. lansoprazole has relatively high solubility in solutions with high pH an d is well partitioned from aqueous to n-octanol phase. Under conditions exami ned in this study, lansoprazole was not hydroscopic and did not decompose a t higher relative humidities.