Novel ophthalmic nanotechnology - Advantages and physicochemical evaluation of ophthalmic nanoemulsion
The eye is a highly compartmentalized organ, and its anatomical structure has many self-protective barriers, which also constitute a barrier for drug delivery. The eye is divided into an anterior segment and a posterior segment. The anterior segment includes the cornea, conjunctiva, iris, aqueous humor, and ciliary body, and the posterior segment includes the vitreous, retina, choroid, and sclera. The physiological barriers of the eye include the cornea and conjunctiva barrier, the blood aqueous humor barrier, and the blood-retinal barrier, among which the cornea and retina are barriers that are difficult for drugs to penetrate. [1] Most ophthalmic drugs sold in the market are in the form of eye drops, eye ointment and ophthalmic gel for external use, which have extremely low bioavailability and basically do not enter the posterior segment of the eye. [2] In addition to traditional ophthalmic solutions, emulsions, suspensions, gels, and ointments, increasing interest has shifte...