Recent progress in sustained/controlled oral delivery of captopril: an overview.

The development of oral sustained or controlled release dosage form of captopril has been an interested topic of research for a long period of time. Difficulties encountered with such topic based on the fact that the drug is freely water soluble and for obvious reasons, such drug is difficult to be delivered orally in a sustained or controlled release manner and, on another hand, the drug is unstable in the alkaline pH of the intestine, which enabled the scientists to localize the developed formulations at the targeted areas of the GIT. Due to its effectiveness and intensive use as a drug of choice in the treatment of hypertension and congestive heart failure, numerous sustained and controlled release formulations of captopril have been made and reported. Despite of these numerous attempts and works, very few have been successful and some of these formulations have been patented. The clinical supportive data regarding the efficacies of these developed formulations are not always available and, furthermore, their claims rely only on in vitro data.