Design, synthesis, fabrication and in vitro evalution of mucoadhesive 5-amino-2-mercaptobenzimidazole chitosan as low water soluble drug carriers

• Mucoadhesive MBI-MA-chitosan was designed and synthesized for low water soluble drug carrier.
• MBI-MA-chitosan can encapsulate hydrophobic SV at >80% compared to 53% with chitosan.
• MBI-MA-chitosan can be easily fabricated as well-formed microparticles using EI.
• MBI-MA-chitosan yields a fivefold higher SV release rate than pure SV.

Mucoadhesive thiolated chitosan suitable as a carrier for low water soluble drugs was designed and synthesized by conjugating 5-amino-2-mercaptobenzimidazole (MBI) using methylacrylate (MA) as the linking agent. A 14.4% degree of substitution of MA, as determined by 1H NMR analysis, and 11.86 ± 0.01 μmol thiol groups/g of polymer, as determined by Ellman’s method, was obtained. The MBI-MA-chitosan had an 11-fold stronger mucoadhesive property compared to unmodified chitosan at pH 1.2, as determined by the periodic acid: Schiff colorimetric method. Chitosan, MA-chitosan and MBI-MA-chitosan were fabricated as well-formed microspheres using electrospray ionization, including an entrapment efficiency of simvastatin (SV) of over 80% for the MBI-MA-chitosan. The mucoadhesiveness of the SV-loaded MBI-MA-CS microspheres was still higher than that for SV-loaded chitosan at pH 1.2 and 6.4. The SV-loaded MBI-MA-CS microspheres revealed a reduced burst effect and an increased release rate (more than fivefold higher than pure SV) of SV over 12 h.

Figure optionsDownload high-quality image (190 K)Download as PowerPoint slide