Press coated bioadhesive pulsatile tablet of lisinopril for chronotherapy of cardiac disorders: In-vitro evaluation

The purpose of present investigation was to formulate bioadhesive pulsatile release tablet (BPRT) of lisinopril drug belong to antihypertensive category for chronotherapy of cardiac disorder. The concept behind this dosage form development is to investigate effect of coating polymer concentration on lag time and drug release from directly compressed tablet. The core tablets prepared by using various concentrations of disintegrants found suitable for complete release of drug in acidic medium indicating its solubility in gastric fluid. The FT-IR studies indicate that selected polymers are compatible with lisinopril since no interaction found in drug-excipient compatibility studies. The dissolution study clearly indicates that higher concentration of polymers which is HPMC K100M and Carbopol reduces free water volume and increase viscosity of the tablet coat causes reduction in drug release. The prepared Bioadhesive pulsatile release tablets showed desired hardness and good mucoadhesion strength. The obtained results showed capability of formulated bioadhesive pulsatile drug delivery system in a drug release for a programmable period of time to attain drug release after minimum 3 hr of Lag time. A stability results clearly indicate that developed pulsatile product was sufficiently stable under accelerated and controlled conditions. Thus, the developed pulsatile tablet can be considered to be a promising formulation for the relief of early morning surge in blood pressure and other cardiac disorders which follows a circadian rhythm.