Chronset® system

In the Chronset system (Fig. 11), the driving force for the drug release was an osmotically active layer in the semipermeable vessel, which pushed the cap out off the impermeable vessel after a predetermined time interval.f The complete release of the drug, often problematic in capsular-shaped dosage forms, was ensured by an expanding layer at the bottom of the capsule body. 

Various pulsatile release methods for oral drug delivery include the Port system (a semipermeable capsule containing an osmotic charge and an insolnble ping) and Chronset system (an osmoticaUy active compartment in a semipermeable cap). 

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