Formulation and characterization of chitosan nanoparticles to enhance transdermal delivery of cinnarizine.

Cinnarizine (CN) is an antihistaminic drug that is commonly used for the treatment of chronic conditions for the reduction of cerebral blood flow such as vertigo. However, CN is poorly water soluble with erratic absorption and low bioavailability. Chitosan is a biodegradable natural polymer with approved skin permeation enhancement properties; therefore, the formulation of CN-loaded chitosan nanoparticles could enhance the skin permeability of CN. In this work, for the first time, CN-loaded chitosan nanoparticles were prepared (using the nanoprecipitation method) and characterized. Additionally, the described nanoparticles were subjected to in vitro release and ex vivo permeation studies. Dynamic light scattering (DLS) characterization showed that the method was successful in the production of small (down to 12.4 nm), positive, and relatively homogenous or monodispersed nanoparticles. The highest entrapment efficiency (EE) of CN in the chitosan nanoparticles was 62±2.7%. Further, the release study showed that chitosan nanoparticles can effectively reduce the burst release and create a sustained release pattern of CN. The ex vivo permeation study, using rat skin as a model, showed that chitosan nanoparticles improved the CN permeability three times compared to the control. In conclusion, chitosan used as a nanocarrier enhances drug penetration in to the skin which may lead to the formulation of a transdermal formulation of CN