The present research work is to design and evaluate an oral time dependent, pulsatile drug delivery system containing Salbutamol Sulphate, which can be targeted to time dependent manner, to modulate the drug level in synchrony with the circadian rhythm of nocturnal asthma. A time dependent pulsatile dosage form was developed by using a various grade of HPC in compressed coated layer. A pulsatile 'Tablet in Tablet' dosage form, taken at bed time with a programmed start of drug release early in morning hours, can prevent a sharp increase in the incidence of asthmatic attacks, during the early morning hours (nocturnal asthma), a time when the risk of asthmatic attacks is the greatest.

The objective of this study is to develop controlled porosity osmotic pump tablet of Verapamil Hydrochloride, which is an antihypertensive candidate, using Polyethylene glycol (PEG) 400 as pore former in Cellulose acetate semipermeable membrane and Mannitol as a osmotic agent which release drug for extended period of time (24 h) and drug release of optimized formulation is independent of pH and agitation speed with zero order release.