Oral Pulsatile Delivery Systems – Applications and Design Strategies

In the field of oral delivery, pulsatile release dosage forms are drawing an increasing interest. After administration, these systems are able to elicit programmable lag phases followed by a prompt or rate-controlled liberation of drugs. Such a release mode has been described as potentially suitable for accomplishing chronotherapeutic goals particularly in the case of widespread chronic pathologies with prevailing night or early-morning symptoms, such as bronchial asthma and cardiovascular disease. Moreover, time-dependent colon delivery can also be achieved when pulsatile delivery systems are conveniently adapted to overcome the variability in gastric emptying time and yield lag phases approximately corresponding to the small intestinal transit time. A delayed liberation of drugs has been attained through a range of formulation approaches, namely reservoir, capsular and osmotic release platforms. Based on these premises, the aim of the present review is to outline the rationale behind oral pulsatile delivery and the main relevant design strategies.