Development and Characterization Pulsatile Microspheres of Nifedipine for Hypertension

Background: To develop pulsatile microspheres of Nifedipine blend of polymers Carbopol 971P and Eudragit RS100 for antihypertensive to release the drug at a particular lag time. Methods: Pulsatile nifedipine microspheres were prepared using the blend of Carbopol 971P and Eudragit RS100 at different ratios in a mixture of solvents. Formulations were prepared and optimized on the basis of particle size, percentage yield and drug entrapment efficiency. Optimized formulations were further analyzed at different resolutions per minute (rpm) by optical microscopy, scanning electron microscopy (SEM), in-vitro dissolution studies and kinetics model. The most promising formulation was compared with the marketed products. The recent patents on microsphere used for hypertension for drug used Liensinine (CN104757561). Dopamine antagonist (US20030069232A1), Human Serum Albumin (EP19990304616) and Omeprazole (IN2107/DEL/2014) helped in selecting the drug and polymers. Results: The formulated microspheres had mean particle size ranging from 177.31 to 277.48 µm. Formulation F83 showed slow release of drug initially for 4 h and drastically release of drug enhanced at a particular lag time (Showed pulsatile release) after 6 h. However, conventional marketed products showed maximum release initially at 1 h and decreased gradually while controlled released marketed product showed sustained pattern. Conclusion: On the basis of data formulation F83 showed slow release and at a particular lag time followed by pulsatile release pattern and followed first order kinetics model. It was concluded that the formulated nifedipine pulsatile dosage form could be useful in the treatment of hypertension.