Application of Layer-by-layer Assembly for Controlled Drug Release from Polyglycolide Nanoparticles

Abstract

Over the past years, topical ophthalmic drug administration has been limited due to low bioavailability. Conventional eye drops have approximate 95% loss, and the washout can result in significant side effects. Ointment was employed to prolong the residence time of the drug at the eye surface, but the application can result in irritation and blurry vision. Although some invasive methods (ex. intravitreal injection) were developed for direct delivery of the drug, these methods have various drawbacks, such as poor patient compliance and possibility of retina detachment by frequent applications. To improve sustained delivery of drugs to the eye in a non-invasive way, we designed a novel core-shell nanoparticle that can be easily applied in a suspension. The core nanoparticles were fabricated by loading lidocaine as a model drug within polyglycolide nanoparticles. Then the core nanoparticles were coated alternatively with oppositely charged type I collagen and chitosan to obtain multilayers. FTIR spectra and variation of zeta potential were employed to demonstrate successful drug loading in the core and layer growth of the shell, respectively. The resulting core-shell nanoparticles were found to be oval in shape, 391.2 4.5 nm in diameter, and loaded with 1.82 0.20 wt. % of lidocaine (model drug). The in vitro drug release was measured for 20 days showing no sudden burst and close to a first order release profile. The shell showed slight modification of release rate at the beginning of the release test.