Background: Chronotherapeutics, the drug delivery based on circadian rhythm, is recently
gaining much attention worldwide. Various diseases like asthma, hypertension, and arthritis
show circadian variation that demands time scheduled drug release for effective drug action.
So, Pulsatile drug delivery system have been designed to confer preprogrammed drug
Objective: In the present study, a ‘3 Cap’ pulsatile drug delivery system has been developed,
optimized and characterized in order to achieve floating and pulsatile release of Ramipril.
Methods: An optimal response surface design was employed to investigate the effect of
isopropanol: formaldehyde vapours for varying time on drug release from the capsules. ‘3
Cap’ pulsatile drug delivery system was evaluated in terms of floating time, density, effect of
gastric flow rate and type of dissolution apparatus on drug release.
Results: Independent variables exhibited significant effect on the drug release of the prepared
formulations. Results showed that time between the release of fractions of dose increased
with increase in formaldehyde: isopropanol ratio and duration of exposure to formaldehyde
vapours with no effect of gastric flow rate.
Conclusion: The design results revealed that an optimum exposure of 1:2 of isopropanol:
formaldehyde vapours for sixty minutes resulted in desired release of second pulse of dose
after a predetermined lag time of 5 hours as desired. ‘3Cap’ system was successful in
achieving floating and pulsed release of hypertensive drug opening a ‘new lease of life’ to the
existing drug molecule.