Chitosan based polymer-lipid hybrid nanoparticles for oral delivery of enoxaparin.

In the present study, chitosan based polymer-lipid hybrid nanoparticles (PLNs) were prepared by a self-assembly method and their use as the carrier for oral absorption enhancement of enoxaparin was evaluated. The enoxaparin-loaded nanoparticles were composed of chitosan as the polymer and glyceryl monooleate as the lipid with a lipid/polymer mass ratio ranging from 0 to 0.3, and F127 was added as a stabilizer. It was found that the PLNs showed a higher surface hydrophobicity but mucoadhesive properties similar to those of chitosan based nanocomplexes. Results from DSC experiments and NMR solvent relaxation study indicate that glyceryl monooleate was completely incorporated into the nanoparticles and the lipid/polymer ratio affected the extent of lipid-polymer interaction inside the nanoparticles and the resultant internal structures. The stability of the PLNs in simulated gastrointestinal fluids was also affected by the lipid/polymer ratio; the best stability was shown by nanoparticles with a lipid/polymer ratio of 0.2. Nanoparticles with the optimal composition significantly enhanced the oral bioavailability of enoxaparin with a 4.5-fold increase in AUC in comparison with a solution of enoxaparin. In conclusion, GMO/CS based PLNs can provide a new insight to develop orally applicable delivery system for hydrophilic macromolecules. Their absorption can be enhanced with proposed PLNs and preparation of this PLNs was also found to be easy comparing to other similar methods.