ANTIGLAUCOMATOUS ACTIVITY OF BETAXOLOL CHLORHYDRATE SORBED ONTO DIFFERENT ISOBUTYLCYANOACRYLATE NANOPARTICLE PREPARATIONS

The objectives of the present work were to evaluate the effects, on the reduction of the intra-ocular pressure (IOP) in glaucomatous rabbits, of different physico-chemical parameters such as: (1) the adsorption percentage of an antiglaucomatous drug (betaxolol chlorhydrate) onto isobutylcyanoacrylate nanoparticles; (2) the binding type of the drug onto the surface of the particles (hydrophobic or electrostatic). By modification of the surface charge, it was possible to adsorb either 25, 30 or 70% for the same drug concentration. When administered in glaucomatous rabbits, in comparison with commercial eye drops, the suspension with the highest adsorption level considerably lowered the overall therapeutic activity. The suspension with the lowest drug payload did not significantly increase the maximal intensity of the therapeutic response and tended to prolong the reduction of the IOP in time. It has been clearly shown that, regarding the ocular administration, the surface charge of the particles and the binding type of the drug onto the nanoparticles were much more important parameters than the drug adsorption percentage onto the nanoparticles. © 1990.