Abstract: A process is described for preparing stabilized tablet formulations for temperature and moisture sensitive active drugs. Water soluble polyvinyl alcohol is processed with drugs such as angiotensin converting enzyme (ACE) inhibitors and compressed into solid form once excess water is removed. Low dose polyvinyl alcohol ramipril tablets prepared by this process are stable under conditions of high humidity and heat for periods of at least up to six months with less than 8% hydrolysis of the prodrug to the active metabolite diketopiperazine (DKP).