Ocular Delivery of Polyphenols: Meeting the Unmet Needs

Abstract

Nature has become one of the main sources of exploration for researchers that search for new potential molecules to be used in therapy. Polyphenols are emerging as a class of compounds that have attracted the attention of pharmaceutical and biomedical scientists. Thanks to their structural peculiarities, polyphenolic compounds are characterized as good scavengers of free radical species. This, among other medicinal effects, permits them to interfere with different molecular pathways that are involved in the inflammatory process. Unfortunately, many compounds of this class possess low solubility in aqueous solvents and low stability. Ocular pathologies are spread worldwide. It is estimated that every individual at least once in their lifetime experiences some kind of eye disorder. Oxidative stress or inflammatory processes are the basic etiological mechanisms of many ocular pathologies. A variety of polyphenolic compounds have been proved to be efficient in suppressing some of the indicators of these pathologies in in vitro and in vivo models. Further application of polyphenolic compounds in ocular therapy lacks an adequate formulation approach. Therefore, more emphasis should be put in advanced delivery strategies that will overcome the limits of the delivery site as well as the ones related to the polyphenols in use. This review analyzes different drug delivery strategies that are employed for the formulation of polyphenolic compounds when used to treat ocular pathologies related to oxidative stress and inflammation.

Balsam Poplar Buds: Extraction of Potential Phenolic Compounds with Polyethylene Glycol Aqueous Solution, Thermal Sterilization of Extracts and Challenges to Their Application in Topical Ocular Formulations

“…Much attention is paid to ophthalmic preparations with biologically active compounds of natural origin, which are applied as anti-inflammatory and antioxidant agents [ 1 , 2 ]. This is due to the fact that in today’s society, with the fast pace of life and high flow of technology, eyes are subject to a lot of strain, fatigue and frequently develop dry eye syndrome and sensitivity, which leads them being more prone to infections [ 1 , 2 ]. Research shows a link between oxidative stress and ocular surface diseases [ 3 , 4 ] and one of the common solutions is the use of topical preventive eye products.…”

Can Nutrition Play a Role in Ameliorating Digital Eye Strain?

“…Flavonoids, a large group of polyphenolic compounds found in a variety of plant species, demonstrate unique medicinal properties for ocular health to support the rationale for their inclusion in nutritional strategies for ameliorating signs of digital eye strain [ 182 ]. Among them, anthocyanins have been widely used in traditional medicine specifically for improving scotopic vision and alleviating eye fatigue in older adults [ 183 , 184 , 185 ]. These phytochemicals demonstrate remarkable anti-oxidative, anti-inflammatory, and immunomodulating properties [ 182 , 183 , 184 , 185 , 186 , 187 , 188 , 189 ].…”

“…Among them, anthocyanins have been widely used in traditional medicine specifically for improving scotopic vision and alleviating eye fatigue in older adults [ 183 , 184 , 185 ]. These phytochemicals demonstrate remarkable anti-oxidative, anti-inflammatory, and immunomodulating properties [ 182 , 183 , 184 , 185 , 186 , 187 , 188 , 189 ].…”

Ophthalmic In Situ Gels with Balsam Poplar Buds Extract: Formulation, Rheological Characterization, and Quality Evaluation

“…The causative agents of these diseases are viruses, bacteria, fungi, and protozoa [ 3 ]. With the increasing popularity of natural aids, the demand for natural ophthalmic preparations is growing as well, but the use of natural materials in ophthalmology should be based on scientific research [ 3 , 4 ]. The data from scientific research show that rational nutrition and consumption of fruit and vegetables help to preserve vision and even reverse vision disorders [ 4 , 5 ].…”

“…With the increasing popularity of natural aids, the demand for natural ophthalmic preparations is growing as well, but the use of natural materials in ophthalmology should be based on scientific research [ 3 , 4 ]. The data from scientific research show that rational nutrition and consumption of fruit and vegetables help to preserve vision and even reverse vision disorders [ 4 , 5 ]. That positive effect is associated with the presence of some phytochemicals, which have bioactive properties, such as polyphenols and carotenoids [ 5 ].…”