Ophthalmic Drug Delivery Systems (Review)
Introduction. Effective delivery of ophthalmic drugs is challenging. The eye has a number of protective systems and physiological barriers, which is why ophthalmic dosage forms have a low bioavailability, usually not exceeding 5 %. Topical drug administration is relatively easy to use and is most commonly prescribed by physicians for the treatment of ophthalmic diseases, especially the anterior segment of the eye. However, when using traditional delivery systems, a number of problems arise: patients' violation of the drug administration technique, and, as a consequence, a decrease in treatment compliance, restriction of drug delivery to the target eye tissues due to low epithelial permeability and rapid clearance after drug administration. Maintaining a constant therapeutic drug level is another challenge that traditional delivery systems often fail to cope with.Text. The article discusses the types of ophthalmic delivery systems. Traditional ones are represented by such dosage forms as eye drops, ointments, gels. Modern ophthalmic dosage forms are represented by: eye films, contact lenses and eye implants. The characteristics, advantages and disadvantages of each type of delivery systems and their promising directions of development, as well as modern developments in this area are given.Conclusion. Currently, most of the scientific research on the development of ophthalmic delivery systems is devoted to obtaining dosage forms capable of maintaining a constant concentration of the drug in the target tissue, providing the transport of active ingredients to them. This is achieved by using modern advances in nanotechnology and polymer chemistry. Receive liquid and soft dosage forms with micro-, nano- and micro-nano-carriers. Polymeric delivery systems such as films, lenses and implants are being actively developed and studied. The development of modern technological approaches opens up new possibilities for the treatment of a wide range of ophthalmic diseases by reducing the side effects often induced by the intrinsic toxicity of molecules, reducing the frequency of the administered dose and maintaining the pharmacological profile of the drug. Thus, the use of modern ophthalmic delivery systems can significantly limit the use of invasive treatments.