Abstract: Water-soluble dispersions of chlorthalidone are prepared by a process comprising:(a) forming a solution comprising a water soluble pharmaceutically acceptable polymeric carrier and a C.sub.1 -C.sub.4 alkanol,(b) dissolving chlorthalidone in the solution thus formed, and(c) removing the C.sub.1 -C.sub.4 alkanol from the solution by evaporation,the amount of said carrier being effective to suppress substantially the formation of the alkyl ether by-product from the reaction of chlorthalidone with the C.sub.1 -C.sub.4 alkanol. A preferred water soluble carrier is polyvinylpyrrolidone and a preferred C.sub.1 -C.sub.4 alkanol is methanol.