PREPARATION AND ⁢IN VITRO⁢ CHARACTERIZATION OF AMLODIPINE PULSATILE MICROSPHERES FOR HYPERTENSION

The aim was to develop pulsatile microspheres of amlodipine drug release with a blend of microspheres and pulsatile principles of drug delivery system to modify drug release pattern and to release the drug at a particular time on the basis of lag time. Microspheres were prepared by the solvent evaporation method using Eudragit S100 as an enteric acrylic polymer with amlodipine at various polymer/drug ratios in a mixture of 0.2% PVA and chloroform. Different formulations were prepared using different ratios of polymer at various RPM (resolutions per minute) such as 500, 750, 1000, 1250 and 1500. Formulations were evaluated for micrometric properties. scanning electron microscopy and dissolution studies. Selected the most promising formulations were compared with the marketed product. Formulation F5 showed slow release of drug initially and drastically releases of drug enhanced at a particular lag time (showed pulsatile release).However. in case of marketed products the formulation showed maximum release initially and decreased gradually release of drug during the 8 h study. It was concluded that the formulation F 5 containing drug amlodipine showed slow release and at a particular lag time followed pulsatile release pattern and showed Highuchi model kinetics. The pulsatile dosage form of drug could be useful in chronopharmacotherapy of the treatment of hypertension.