A Self Emulsifying Drug Delivery System (SEDDS) for Nisoldipine: Characterization, Dissolution and Conversion into Solid Sedds

Poorly soluble drugs such as nisoldipine offer challenges in developing a drug product with adequate bioavailability. The objective of present study was to improve solubility and dissolution rate of nisoldipine by developing and characterizing self emulsifying drug delivery system (SEDDS) of nisoldipine. Solubility of nisoldipine was carried out in various oils, surfactants and co-surfactants. Six self emulsifying formulations were prepared using various proportions of oil, surfactants and co-surfactants in which solubility of nisoldipine was high. The stability studies after introduction of nisoldipine into different combinations provided the optimized liquid SEDDS comprising of capmul MCM EP, labrasol, tween 60 and polyethylene glycol 400, which was then evaluated for droplet size, percentage transmittance and coalescence studies. Liquid SEDDS was then converted into free flowing powder by adsorbing onto solid carriers. Solid state characterization of solid SEDDS was performed by scanning electron microscopy (SEM) and differential scanning calorimetric (DSC) measurements. The comparative dissolution studies with nisoldipine and SEDDS proved the efficiency of self emulsifying formulations in improving dissolution rate. The permeability studies as non everted sac method gave higher permeation rate for SEDDS. This solid SEDDS may provide a useful solid dosage form for oral poorly soluble drugs.