Nocturnal asthma is a condition prevalent in two-third of asthmatics, in which there is variable night time exacerbations of asthmatic conditions associated with worsening of lung function. Asthmatic attacks occur especially around 4 am. Theophylline (dimethylxanthine), is a methylxanthine drug used in therapy for respiratory diseases such as COPD and asthma. This study attempts to design and evaluate a chronomodulated drug delivery system of theophylline with a lag time of 6 hours. The present work is aimed to design a pulsatile tablet with a core which contains a disintegrant with swelling property, coated with a pH dependent polymer. The coating ruptures when the fluid enters the core as the disintegrant swells. The percentage weight gain in coating is varied from 1 to 8%. The coated tablets showed a proportionate increase in lag time with increase in the coating level (147 to 438 mins. for coating of 1 to 8% respectively). Further, this proportionality was utilized to optimize the formulation, 32 factorial design was applied considering superdisintegrant concentration and coating level as the factors for three levels. The results revealed that the lag time increases with increase in coating level and decreases with increase in concentration of superdisintegrant. The batch with 4 % of superdisintegrant and 6 % weight gain showed desired lag time Ã?Å? 6 hrs. with desirable In-vitro drug release profile. The optimized formulation complied with the ICH stability testing guidelines. The developed pulsatile tablet formulation thus produced promising results for oral delivery.
Loading....