Abstract:
The objective of this study was to design and developed a capsule dosage form which contains the drug closed with plug, which is removed after a predetermined lag time and the drug is release from the insoluble capsule body early in the morning hours. This delivery system was helpful to control early morning surge in blood pressure because cardiovascular events occur more frequently in the morning. Initially core tablet was prepared by using Captopril as a model drug, which is having Angiotensin-converting enzyme inhibition activity and different concentration of crosscarmellose sodium as a super disintegrant by the direct compression method by using 6 mm flat faced punch. Formulation was developed by filling core tablets in formaldehyde treated empty capsule body and sealed by using plugs of different polymers like guar gum, HPMC K4M, Sodium alginate and Xanthum Gum. Core tablet was evaluated for different evaluation parameters and the formulation which shows least disintegration time has been selected for further study. After complete wetting of the plug, it formed a soft mass, which was then easily ejected out of the capsule body expose the core tablet of captopril to pH 6.8 phosphate buffer (simulated colonic fluid). From in vitro dissolution study it was concluded that, the drug release is directly proportional to concentration of polymer used in erodible tablet plug.

Keywords: Pulsatile Drug Delivery, Hypertension, Chronotherapy, Captopril, Lag Time.