Summary.

Poly(lactide-co-glycolide) nanoparticles containing pilocarpine hydrochloride as a model drug were prepared by a double emulsification method using polyvinylalcohol (PVA) Carbopol or their mixture either as stabilizers or as coating agents. The larger size and more negative zeta-potential of the nanoparticles formulated with Carbopol suggested the formation of a coating layer on their surface. This process was not well pronounced in the case of PVA/Carbopol prepared nanoparticles due to intermolecular interaction between both agents. The mucoadhesive properties of Carbopol-modified nanoparticles were considered comparing their surface charge before and after incubation into mucin dispersion. The reduction of the negative value denoted that mucin and Carbopol-coated nanoparticles interacted, which could lead to a longer precorneal residence time.