Preparation of chitosan particles using ultrasonic atomization for controlled drug release

Abstract

Chitosan particles with the sizes ranging from 250 to 1,520 nm was prepared from chitosan solution using an electrospray equipped with an ultrasonic atomizer. The chitosan particles were spherical and had smooth surface. The effects of preparation parameters on particle size were investigated. The size of dry chitosan particles tended to increase but not statistically significant when the molecular weights increased from 47 to 238 kDa. But in the hydrated state the particle sizes incresed significantly with increasing the MW. In order to get small CS particle size, CS with high DD and low CS concentration should be used. Increasing the lidocaine drug content tended to significantly increase the size of dry particles but not the hydrated particles. Increasing in hydrogen bonding between chitosan and lidocaine was observed by IR analysis. The lidocaine content within CS-LC-Ps was increased with the increasing drug to chitosan ratio but decreased with chitosan molecular weight increased. The entrapment efficiency of 90% could be successfully achieved. Up to 92% of lidocaine was released from chitosan particles into phosphate buffer solution (pH 7.4) at 37 °C within the period of 3 hours with no significant burst of drug during the initial hydrated stage. Finally, a simulated skin permeation study of the lidocaine from chitosan particles using shed snake skin and cellulose membrane demonstrated that lidocaine was continuously released from the particles for up to 6 hours of study