Selection of polymer materials for the production of eye drops with diclofenac sodium salt

Abstract

Vision is a primary sense that provides a distinct survival advantage to most animals. Topical ophthalmic non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in veterinary medicine to control chronic or acute low-grade ocular inflammation such as anterior uveitis and corneal epithelial lesions, as well as to reduce post-operative inflammation after phacoemulsification surgery. However, the difficulty in administering the drug to the tissues of the eye still leads to a number of challenges. The eye has a unique anatomy and physiology, but due to effective protective mechanisms and functions of the corneal barrier in the eye, limited bioavailability of eye drops occurs in the eye, short absorption time, which makes it difficult to get the necessary drug concentration to the site of damage, so a large part of the eye drops is washed out of the eye with tears. Less than 5 percent is absorbed lipophilic molecules and less than 0.5 percent hydrophilic molecules, so the viscosity of the eye drops helps to keep the active substance on the surface of the eye longer . One of the most important tasks in the production of an ophthalmic dosage form is the selection of the base - medicinal substances must be evenly distributed in the base. Their release depends on the composition of the base and the characteristics of the drug substance. The base must not react with other components, not change due to environmental factors, not cause allergies and must not irritate the tissues of the eye. The substance used for the base must effectively release the medicinal substance so that it reaches the site of action, maintain the necessary concentration of the medicinal substance to cause the required pharmacological effect. These are important factors that must be taken into account when choosing excipients for the production of eye drops. In this study, diclofenac sodium salt (diclofenac) was selected as the active ingredient due to its anti-inflammatory, analgesic properties, capable of managing pain and inflammation in eye diseases. The selected concentration of diclofenac sodium salt in eye drop formulations is 0.1 percent. [1]. A major challenge in modeling a hydrophilic ophthalmic formulation with diclofenac is its poor water solubility. Therefore, it is necessary to select excipients that would increase the stability of diclofenac. Polymeric materials were used as the bases of the formulations. Ophthalmic bases with polymers, chosen to increase the viscosity of the pharmaceutical form, reduce the washout of the drug with tears and prolong the contact time of the drug with the eye surface, and increase bioavailability. Natural and synthetic polymers have been shown to be useful in ophthalmic formulations due to their viscosity-enhancing properties [ 2 ]. Chitosan and poloxomer P407 were selected for the production of ophthalmic bases. [...].