Inflammation plays a key role in dry eye disease (DED) affecting millions of people worldwide. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used topically to act on the inflammatory component of DED, but their limited aqueous solubility raises formulation issues. The aim of this study was development and optimization of functional cationic nanoemulsions (NEs) for DED treatment, as a formulation approach to circumvent solubility problems, prolong drug residence at the ocular surface and stabilize the tear film. Ibuprofen was employed as the model NSAID, chitosan as the cationic agent, and lecithin as the anionic surfactant enabling chitosan incorporation. Moreover, lecithin is a mixture of phospholipids including phosphatidylcholine and phosphatidylethanolamine, two constituents of the natural tear film important for its stability. NEs were characterized in terms of droplet size, polydispersity index, zeta-potential, pH, viscosity, osmolarity, surface tension, entrapment efficiency, stability, sterilizability and in vitro release. NEs mucoadhesive properties were tested rheologically after mixing with mucin dispersion. Biocompatibility was assessed employing 3D HCE-T cell-based model and ex vivo model using porcine corneas. The results of our study pointed out the NE formulation with 0.05 % (w/w) chitosan as the lead formulation with physicochemical properties adequate for ophthalmic application, mucoadhesive character and excellent biocompatibility.

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Olive pomace is a rich source of biologically active compounds, mainly polyphenols. Recently, an efficient and sustainable cyclodextrin (CD)-enhanced extraction was developed. It enabled a relatively simple formulation of high-quality olive pomace extracts (OPEs) that can be used as alternative sources of olive-derived polyphenols in the nutrition and pharma industries. However, biological effects and nutraceutical potential of OPEs are primarily limited by generally low oral bioavailability of major polyphenols (hydroxytyrosol and its derivatives) that can be significantly influenced by OPE matrix and the presence of CDs in formulation. The major goal of this research was to investigate the impact of complex matrix and different types of CDs on gastrointestinal stability and intestinal permeability of major OPE polyphenols, and provide additional data about mechanisms of absorption and antioxidant activity in gut lumen. Obtained results showed high bioaccessibility but relatively low permeability of OPE polyphenols, which was negatively affected by OPE matrix. CDs improved antioxidant efficiency of tested OPEs and tyrosol gastrointestinal stability. Effects of CDs on permeability and the metabolism of particular OPE polyphenols were CD-and polyphenol-specific.Nutrients 2020, 12, 669 2 of 16 oxidative stress in the intestine is particularly important given that numerous studies have shown that oxidative stress is directly linked to the development of diseases of the GI tract, such as inflammatory bowel disease and tumor colon. The intestine is the site that was shown to be extremely susceptible to oxidative stress. Namely, lipid peroxidation (as a chain reaction that lead to deleterious cell membrane damage) can be initiated by dietary fats.Considering its phenolic composition, olive pomace is very similar to olive oil and represents an inexpensive and readily available source of HTS derivatives. In the last decade, the potential of the olive pomace as a rich source of biologically active compounds has been recognized in scientific and professional literature, resulting in the development of a large number of effective extraction procedures [6,7]. However, the poor technological properties of raw olive pomace extracts (OPE) limit their wider application as nutraceuticals and food additives [7]. The main prerequisites for obtaining usable OPE are high yield of HTS derivatives, stability, and satisfactory technological properties of dry extracts. In this regard, cyclodextrins (CDs) were successfully applied for achieving higher polyphenol yields and the formulation of stable and organoleptically acceptable olive pomace extracts (OPEs) [7]. Moreover, α-CD, β-CD, and γ-CD are listed on the generally regarded as safe (GRAS) list of the U.S. Food and Drug Administration (FDA) for use as a food additive [8][9][10].In addition to demonstrating favorable chemical composition and technological properties, the quality of OPE is significantly determined by bioavailability and biological activity of its main active components...

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Oil-in-water nanoemulsions (NEs) represent one of the formulation approaches to improve eye-related bio-availability of lipophilic drugs. The potential of cationic NEs is pronounced due to the electrostatic interaction of positively charged droplets with negatively charged mucins present in the tear film, providing prolonged formulation residence at the ocular surface. The aim of this study was to develop a cationic ophthalmic NE with cationic lipid stearylamine (SA) as a carrier of a positive charge. The addition of a nonionic surfactant provided the dual electro-steric stabilization of NEs and enabled tuning of SA concentration to achieve an optimal balance between its interaction with mucins and biocompatibility. Physicochemical characterization, stability profile, in vitro mucoadhesion study and biocompatibility study employing 3D HCE-T cell-based model of corneal epithelium pointed out the NE with 0.05 % (m/m) SA as the leading formulation. Minimizing SA content while retaining droplet/mucin interactions is of great importance for efficacy and safety of future ophthalmic drug products.