In vitro-in vivo evaluation of olopatadine incorporated chitosan nanoparticles for the treatment of ocular allergy

In this study, antihistaminic agent Olopatadine hydrochloride (OLO) was incorporated into chitosan nanoparticles for the treatment of ocular allergy. Nanoparticles were prepared with spray drying method. Physicochemical properties and efficacy of the formulations were evaluated by in vitro and in vivo studies. SEM analyses were performed for the determination of morphology of the particles. Particle size analyses showed that particles were within the nanometer range (119 ± 9 nm to 227 ± 18 nm) with relatively homogenous size distribution (0.453 ± 0.078 to 0.643 ± 0.124 PDI data). Regarding cationic character of chitosan, nanoparticles were cationic as expected with zeta potentials within the range of +27.8 ± 0.3 mV to +35.5 ± 1.2 mV. DSC, FT-IR and 1H NMR analyses revealed the physical integrity of nanoparticles. High encapsulation efficacy up to 73.33 ± 0.25% were detected by ultra-high performance liquid chromatography (U-HPLC) method. For the determination of corneal residence time of nanoparticles in vivo studies were performed on sheeps. Analyses results revealed that, ocular residence time was enhanced up to 24 h with single instillation. As a result of the study OLO incorporated cationic chitosan nanoparticles remained on the ocular surface for longer periods due to the electrostatic interactions with negatively charged corneal surface, which will provide effective treatment of ocular allergy.