Enhancing Oral Solubility and Permeability of Edoxaban Tosylate Via Development of Self-microemulsifying Drug Delivery System

Abstract

Edoxaban tosylate monohydrate (EDTM) is present in class IV of the biopharmaceutics classification system (BCS), as it is poorly soluble and poorly permeable, which limits its bioavailability. The rationale of this study was to improve the permeability and solubility of EDTM by incorporating it into a self-micro-emulsifying drug delivery system (SMEDDS).  Suitable excipients were selected and evaluated for their compatibility. The solubility of EDTM was evaluated for all excipients (oil, surfactant, and co-surfactants) at different ratios. Olive oil, Kolliphor RH40, and PEG-400 were chosen as the oil, surfactant, and co-surfactants, respectively, and were developed into a SMEDDS by adding 15 mg of EDTM. The optimized EDTM-SMEDDS (F1, F2, F3, and F4) were characterized for particle size, polydispersity index (PDI), zeta potential, stability, in vitro release, and ex vivo permeation studies. F2 showed a particle size of 56.43 ± 1.78, PDI of 0.190 and -3.30 ± 0.56 mV of zeta-potential. The enhanced release and permeability of F2 were observed for all other EDTM-SMEDDSs and raw EDTM dispersions. Upon storage under continuous temperature and accelerated stability conditions, F2 showed no signs of phase separation and was visually clear while retaining the %encapsulation efficiency and drug loading, that is, it was stable. The liquid EDTM-SMEDDS improved the bioavailability of EDTM.