FORMULATION AND IN-VITRO CHARACTERIZATION OF SELF MICROEMULSIFYING DRUG DELIVERY SYSTEMS OF RIVAROXABAN

The drug Rivaroxaban which was poorly soluble was selected for formulation of SMEDDS due to its poor aqueous solubility and its oral bioavailability which is 66%. Self micro emulsifying drug delivery system was developed to improve its solubility and bioavailability. Solubility of Rivaroxaban is determined in various oils, Surfactants, and co-surfactants by UV-Spectrophotometric method. Rivaroxaban has been shown maximum solubility in oil Peceol oil, surfactant Tween 80 and co surfactant Transcutol HP. A series of Pseudo ternary phase diagrams are constructed to identify micro emulsion region. Various compositions of Oil and S_mix are titrated with water to identify micro emulsion region. From pseudo-ternary phase diagrams systems consisting of Peceol oil as oily phase, Tween 80  surfactant, Transcutol HP as co surfactant are selected for formulation. SMEDDS are prepared by selecting oil: S_mix ratio 1:9 ….9:1 and S_mix ratio 1:3, 1:4. Two mixtures (PTWT-2(1:9), PTWT-2(2:8) are selected for formulation of SMEDDS by keeping amount of drug constant (20mg) in all formulations. Prepared formulations are evaluated for Self emulsification and visual assessment, Phase separation and precipitation of the drug, Robustness to dilution, Percentage Transmittance, drug loading efficiency, FT-IR Studies, Thermodynamic stability studies, Droplet size, PDI and Zeta potential. All five formulations are emulsified in 25-30 seconds i.e. in less than 1 min. No formulation had showed precipitation and phase separation of drug. All formulations are robust to dilution. All formulations have shown percentage transmittance more than 95% indicating clear emulsions. All formulations have drug loading efficiency more than 90%. Thermodynamic stability studies had indicated that all formulations are stable after centrifugation and freeze thaw cycle. Droplet size was found to be 215.3nm and Zeta potential – 8.34 nm and FT – IR spectrums shown no interaction between drug and excipients. Cumulative percentage drug release of Rivaroxaban is 81.32%. The SMEDDS formulation clearly showed improved and increased drug dissolution for poorly soluble drug. This helps to keep the drug in soluble state in GIT. So the prepared SMEDDS have capability for delivering poorly water soluble drug Rivaroxaban in soluble state in GIT.