Abstract: The present invention relates to ophthalmic compositions in the form of oil-in-water (O/W) nano-emulsions, and which mainly comprise propylene glycol and sodium hyaluronate. The invention also relates to preparation methods and uses of the artificial tear compositions.

Abstract: The invention relates to a novel solid complex, which is insoluble in an aqueous environment and which, in dry form thereof, can be used to develop novel systems for the sustained release of drugs for ophthalmic use. The invention also relates to a method of preparing said complex. The complex is formulated based on a viscoelastic solution derived from HA (Biovisc®), a therapeutically acceptable drug such as a steroid, quinolone, a non-steroid anti-inflammatory, an immunosuppressor or compatible drug and chitosan, all of which are conjugated such as to produce biodegradable polymer matrices for the treatment of ocular ailments. The invention also relates to a method of preparing the aforementioned matrices. The invention further relates to microspheres and a method of producing same, using the same original materials, in which the therapeutic principle comprises a steroid, quinolone, a non-steroid anti-inflammatory, an immunosuppressor or another drug which is stable and compatible with said system.