Design, Development of Nitrendipin Self-Microemulsifying Drug Delivery

Self-microemulsifying drug delivery system (SMEDDS) of Nitrendipine was aimed at overcoming the problems of poor solubility and bioavailability. The formulation strategy included selection of oil phase based on saturated solubility studies and surfactant and co-surfactant screening on the basis of their emulsification ability. Ternary phase diagrams were constructed to identify the self-emulsifying region. Ethyl oleate as oil, Cremophore RH40 as surfactant and PEG 400 as co-surfactant were concluded to be optimized components. The prepared SMEDDS was characterized through its droplet size, zeta potential, self micro emulsification time and drug content determination. The optimized formulation exhibited 98 % in vitro drug release, which was significantly higher than that of the drug solution. Infrared spectroscopy, differential scanning calorimetric, SEM and x-ray diffraction studies indicated no incompatibility between drug, oil and surfactants. From the stability studies of solid SMEDDS, there was no significant decrease in drug release and drug content, hence the formulation is found to be stable and then Comparative in vitro release study of optimised batch.