Design and Evaluation of Time controlled Pulsatile Drug Delivery Systems for Diseases Following a Circadian Pattern

Abstract

The role of chronotherapeutics in hypertension is based on the recognition that blood pressure does not remain constant throughout the day. Instead, it tends to be higher in the early morning hours and lower in the evening hours. The aim of the present study was to design time controlled outer coat of the tablet which releases the inner core at a lag time of 3/5/7 hrs, as chronopharmaceutical drug delivery system by compression coating. Formulation design involves the coating polymer ratio (1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 w/w etc) of HPMC E5LV and HPMC E10M or HPMC K100M which were exploited for their cracking drug release ability. The basic idea behind the dosage form development is to investigate effect of coating design on lag time and drug release from press-coated pulsatile release tablet. Coating materials-powders were evaluated for pre compression parameters like bulk density, angle of repose, compressibility index, Hausner's ratio and also evaluated the tablet for hardness, thickness, friability, weight variation, drug content and In vitro drug release. The Formulation was optimized on basis of acceptable tablet properties and in vitro drug release. The results indicate that Formulation F21, F22 & F32 for press-coated tablets achieve a burst release after 3/5/7 hrs lag time which is applicable as timed drug delivery system.