scholarly journals Improving Stability of Tear Film Lipid Layer via Concerted Action of Two Drug Molecules: A Biophysical View

2020 ◽  
Vol 21 (24) ◽  
pp. 9490
Author(s):  
Petar Eftimov ◽  
Agnieszka Olżyńska ◽  
Adéla Melcrová ◽  
Georgi As. Georgiev ◽  
Philippe Daull ◽  
...  
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Eye Drops ◽  
Active Components ◽  
Lipid Film ◽  
Drug Molecules ◽  
Air Interface ◽  
Oil In Water ◽  
Surface Active ◽  
Dynamics Simulations

The tear film at the ocular surface is covered by a thin layer of lipids. This oily phase stabilizes the film by decreasing its surface tension and improving its viscoelastic properties. Clinically, destabilization and rupture of the tear film are related to dry eye disease and are accompanied by changes in the quality and quantity of tear film lipids. In dry eye, eye drops containing oil-in-water emulsions are used for the supplementation of lipids and surface-active components to the tear film. We explore in detail the biophysical aspects of interactions of specific surface-active compounds, cetalkonium chloride and poloxamer 188, which are present in oil-in-water emulsions, with tear lipids. The aim is to better understand the macroscopically observed eye drops–tear film interactions by rationalizing them at the molecular level. To this end, we employ a multi-scale approach combining experiments on human meibomian lipid extracts, measurements using synthetic lipid films, and in silico molecular dynamics simulations. By combining these methods, we demonstrate that the studied compounds specifically interact with the tear lipid film enhancing its structure, surfactant properties, and elasticity. The observed effects are cooperative and can be further modulated by material packing at the tear–air interface.

scholarly journals Emulsion Formation and Stabilizing Properties of Olive Oil Cake Crude Extracts

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 633
Author(s):  
Firdaous Fainassi ◽  
Noamane Taarji ◽  
Fatiha Benkhalti ◽  
Abdellatif Hafidi ◽  
Marcos A. Neves ◽  
...  
Keyword(s):  
Olive Oil ◽  
Ethanol Extract ◽  
Active Components ◽  
Oil In Water ◽  
Surface Active ◽  
Ph Conditions ◽  
Oil Water ◽  
Surface Active Compounds ◽  
Ionizable Groups ◽  
Emulsifying Ability

The surface-active and emulsifying properties of crude aqueous ethanolic extracts from untreated olive oil cake (OOC) were investigated. OOC extracts contained important concentrations of surface-active components including proteins, saponins and polyphenols (1.2–2.8%, 7.8–9.5% and 0.7–4.5% (w/w), respectively) and reduced the interfacial tension by up to 46% (14.0 ± 0.2 mN m−1) at the oil–water interface. The emulsifying ability of OOC extracts was not correlated, however, with their interfacial activity or surface-active composition. Eighty percent aqueous ethanol extract produced the most stable oil-in-water (O/W) emulsions by high-pressure homogenization. The emulsions had average volume mean droplet diameters of approximately 0.4 µm and negative ζ-potentials of about -45 mV, and were stable for up to 1 month of storage at 5, 25 and 50 °C. They were sensitive, however, to acidic pH conditions (<5) and NaCl addition (≥25 mM), indicating that the main stabilization mechanism is electrostatic due to the presence of surface-active compounds with ionizable groups, such as saponins.

«Dry eye» syndrome and primary glaucoma: possibilities of treatment

Reflection ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 42-44
Author(s):  
L.I. Solovyova ◽  
◽  
T.V. Gavrilova ◽  
F.G. Mugumova ◽  
◽  
...  
Keyword(s):  
Dry Eye ◽  
Open Angle Glaucoma ◽  
Tear Film ◽  
Dry Eye Syndrome ◽  
Rupture Time ◽  
Eye Drops ◽  
Film Rupture ◽  
Good Tolerability ◽  
Primary Glaucoma ◽  
The Stability

The article presents the results of Ocuhyl C using in the treatment of «dry eye syndrome» (DES) in 47 eyes of 26 patients with different stages of compensated primary open-angle glaucoma. Experience of instillation of hypotensive eye drops with preservatives was from 1 year to 35 years. Assessment of subjective signs of DES was performed by questioning. Functional tests were performed (for the stability of the precorneal tear film –Norn test, for the level of total tear production –Shirmer test). Examinations were carried out at the first examination before prescribing the drug, then after 4 and 8 weeks of its use. All the patients noted good tolerability of the drug, no side effects. Indicators characterizing the feeling of a foreign body, dryness and redness of the eyes have significantly decreased. Precorneal tear film rupture time has significantly increased. Ocuhyl C can be recommended for clinical use. Key words: primary glaucoma; “dry eye” syndrome; tear forming; tear film rupture time; Ocuhyl C.

scholarly journals Cationic Thiolated Poly(aspartamide) Polymer as a Potential Excipient for Artificial Tear Formulations

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mária Budai-Szűcs ◽  
Gabriella Horvát ◽  
Barnabás Áron Szilágyi ◽  
Benjámin Gyarmati ◽  
András Szilágyi ◽  
...  
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Eye Drops ◽  
Thiol Groups ◽  
Physiological Properties ◽  
Disulphide Bond Formation ◽  
Polymer Bearing

Dry eye disease is a relatively common ocular problem, which causes eye discomfort and visual disorders leading to a decrease in the quality of life. The aim of this study was to find a possible excipient for eye drop formulations, which is able to stabilize the tear film. A cationic thiolated polyaspartamide polymer, poly[(N-mercaptoethylaspartamide)-co-(N-(N′,N′-dimethylaminoethyl)aspartamide)] (ThioPASP-DME), was used as a potential vehicle. Besides satisfying the basic requirements, the chemical structure of ThioPASP-DME is similar to those of ocular mucins as it is a protein-like polymer bearing a considerable number of thiol groups. The solution of the polymer is therefore able to mimic the physiological properties of the mucins and it can interact with the mucus layer via disulphide bond formation. The resultant mucoadhesion provides a prolonged residence time and ensures protective effect for the corneal/conjunctival epithelium. ThioPASP-DME also has an antioxidant effect due to the presence of the thiol groups. The applicability of ThioPASP-DME as a potential excipient in eye drops was determined by means of ocular compatibility tests and through examinations of the interactions with the mucosal surface. The results indicate that ThioPASP-DME can serve as a potential eye drop excipient for the therapy of dry eye disease.

Performance of oil-in-water emulsions stabilized by different types of surface-active components

2020 ◽  
Vol 190 ◽  
pp. 110939 ◽  
Author(s):  
Bruna Barbon Paulo ◽  
Izabela Dutra Alvim ◽  
Gary Reineccius ◽  
Ana Silvia Prata
Keyword(s):  
Active Components ◽  
Oil In Water ◽  
Different Types ◽  
Surface Active

scholarly journals Dry eye disease in students with myopia during COVID-19 pandemic

2021 ◽  
Vol 9 (3) ◽  
pp. 34-37
Author(s):  
M.V. Panchenko ◽  
P.A. Bezditko
Keyword(s):  
Distance Learning ◽  
Dry Eye ◽  
Contact Lenses ◽  
Tear Film ◽  
Face Mask ◽  
Corneal Topography ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Eye Drops ◽  
Ocular Surface Disease Index

Background. Today, the urgent problem is coronavirus disease 2019 pandemic in the whole world. Safety measures such as the use of masks, distance learning have been implemented. However, ophthalmologists, as well as the general population, should know that a face mask together with prolonged use of digital devices leads to an increase in the number of dry eye cases in many patients. The purpose was to study the frequency of dry eye disease in students with myopia. Materials and methods. The study involved 96 medical students diagnosed with myopia taken by random sampling, who were examined by an ophthalmologist. Apart from the standard ophthalmologic examination, all patients underwent the evaluation of the stability of the precorneal tear film by means of corneal topography, and Norn test (tear break-up time (TBUT)). There was also used a standard questionnaire designed to assess the severity of dry eye disease symptoms (Ocular Surface Disease Index). Results. The corneal topography of the 47 patients did not demonstrate any reduction in TBUT. The average time of the concentric ring remained stable for 20.2 ± 3.0 seconds. But 49 individuals exhibited signs of tear film instability over time compared to 47 patients without TBUT impairment. In 47 people without impairments, corneal topography demonstrated that this indicator in Norn test varied from 25 to 18 seconds, i.e. was within the age norm (21.5 ± 3.5 seconds on average). In 3 patients with a minimum TBUT on keratotopography, its value during the Norn test was 9 seconds. In 36 patients with reduced TBUT according to both methods, there was a weak degree of dry eyes, in 10 — moderate, in 3 — severe. The most common complaints were a sandy, gritty sensation in the eyes, visual discomfort when working at a computer and in windy weather, and with prolonged use of a protective mask. Conclusions. Among students who were on distance learning, 51.04 % of individuals have objectively confirmed dry eye disease. People wearing contact lenses have a more pronounced degree of dry eye, so it is mandatory for ophthalmologists to prescribe lubricating eye drops.

scholarly journals Effect of a formulated eye drop with Leptospermum spp honey on tear film properties

2020 ◽  
Vol 104 (10) ◽  
pp. 1373-1377
Author(s):  
Jacqueline Tan ◽  
Tianni Jia ◽  
Roslyn Liao ◽  
Fiona Stapleton
Keyword(s):  
Dry Eye ◽  
Evaporation Rate ◽  
Tear Film ◽  
Eye Drops ◽  
Ocular Surface Disease Index ◽  
Film Properties ◽  
Film Evaporation ◽  
Before And After ◽  
Registration Number ◽  
Corneal Staining

AimTo evaluate the effects of a proprietary formulated eye drop with Leptospermum spp honey versus a conventional lubricant eye drop on tear film properties in subjects with symptoms related to dry eye disease after 28 days of treatment.MethodsForty-six subjects with symptoms related to dry eye (Ocular Surface Disease Index (OSDI) score >12) were enrolled and randomly assigned to receive either the test formulated eye drop (Optimel by Melcare Biomedical Pty Ltd) or control eye drops (Alcon, USA) in this double-masked study. Inferior lipid layer thickness (LLT), tear film evaporation rate (TER), fluorescein tear film break-up time (TBUT), corneal staining and subjective symptoms (OSDI and visual analogue scales (VAS)) were measured before and after 28 days of instilling the eye drops.ResultsForty-two subjects completed the study (21 subjects in each group). After 28 days of treatment, TER showed a significantly greater reduction with the formulated eye drop compared with the control (p=0.01). TBUT showed a slight but not statistically significant increase with the formulated eye drop compared with the control (p=0.06), and a significantly greater reduction (improvement) in OSDI scores was observed with the formulated eye drop compared with the control (p=0.01). No significant differences were found between the two groups for inferior LLT, corneal staining and any of the VAS scores.ConclusionsThe formulated eye drops were effective in reducing tear film evaporation rate and were more effective for improving symptoms of dry eye compared with the control eye drops after 28 days of treatment.Trial registration numberNCT03622619.

scholarly journals Efficacy of Topical Mesenchymal Stem Cell Therapy in the Treatment of Experimental Dry Eye Syndrome Model

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Emrullah Beyazyıldız ◽  
Ferda Alpaslan Pınarlı ◽  
Özlem Beyazyıldız ◽  
Emine Rümeysa Hekimoğlu ◽  
Uğur Acar ◽  
...  
Keyword(s):  
Dry Eye ◽  
Secretory Granules ◽  
Phosphate Buffer Solution ◽  
Tear Film ◽  
Microscopic Analysis ◽  
Dry Eye Syndrome ◽  
Eye Drops ◽  
Buffer Solution ◽  
Electron Microscopic ◽  
Mesenchymal Stem Cell Therapy

Purpose. The current study was set out to address the therapeutic efficacy of topically applied mesenchymal stem cells (MSCs) on dry eye syndrome (DES) induced by benzalkonium chloride (BAC) in rats.Methods. Rats were divided into two groups just after establishment of DES. Eye drops containing either bromodeoxyuridine labeled MSCs (n=9) or phosphate buffer solution (n=7) were topically applied once daily for one week. Schirmer test, break-up time score, ocular surface evaluation tests, and corneal inflammatory index scoring tests were applied to all rats at baseline and after treatment. All rats were sacrificed after one week for histological and electron microscopic analysis.Results. Mean aqueous tear volume and tear film stability were significantly increased in rats treated with MSCs (P<0.05). Infiltration of bromodeoxyuridine labeled MSCs into the meibomian glands and conjunctival epithelium was observed in MSCs treated rats. Increased number of secretory granules and number of goblet cells were observed in MSCs treated rats.Conclusion. Topical application of MSCs could be a safe and effective method for the treatment of DES and could potentially be used for further clinical research studies.

scholarly journals Ocular Application of Oleuropein in Dry Eye Treatment: Formulation Studies and Biological Evaluation

2021 ◽  
Vol 14 (11) ◽  
pp. 1151
Author(s):  
Susi Burgalassi ◽  
Erica Zucchetti ◽  
Elena Birindelli ◽  
Silvia Tampucci ◽  
Patrizia Chetoni ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Aqueous Solution ◽  
Dry Eye ◽  
Biological Evaluation ◽  
Point Of View ◽  
Eye Drops ◽  
Scanning Calorimetry ◽  
Lipid Film ◽  
Solution Methods ◽  
Ph Buffer

Background. Oleuropein is already known for its numerous pharmacological properties, but its activity in the ocular field has not yet been investigated. The study aims to verify a possible use of oleuropein (OLE)-based eye drops both in terms of efficacy in dry eye syndrome and stability in aqueous solution. Methods. OLE was co-precipitated with HP-β-cyclodextrin, and the obtained complex was encapsulated into liposomes prepared by hydration of a lipid film composed of Lipoid S100 and cholesterol with different pH buffer solutions. The hydrated vesicles were shrunk by ultrasonication or extrusion. The preparations were characterized from the physicochemical point of view by subjecting them to differential scanning calorimetry, ATR-FTIR, dynamic light scattering analysis, and microscopy. Subsequently, OLE protective activity against hyperosmotic and oxidative stress on rabbit corneal epithelial cells (RCE) was evaluated. Results. The liposomal vesicles obtained after extrusion showed a tendency towards greater encapsulation efficiency (up to 80.77%) compared to that obtained by sonication, and the liposomes hydrated in pH 5.5 solution tended to incapsulate more than the neutral ones. Ultrasonication produced two-dimensional populations of liposomes, the largest of which reached 2149 nm. On the contrary, the extruded liposomes showed homogeneous diameters of about 250 nm. Complexation with cyclodextrin and subsequent encapsulation in liposomes greatly increased the OLE stability in aqueous solution, especially at 4 °C and for the extruded formulations. OLE aqueous solution (OLE7.4-sol, reference) and neutral extruded liposomes (F7.4-e) were well tolerated on RCE cells. Moreover, OLE was able to control the effects of hyperosmolarity on ocular surface cells and to prevent oxidative stress-induced loss of cell viability.

scholarly journals Patients Preference of Diquafosol or Rebamipide Eye Drops for the Treatment of Mild Dry Eye: A Pilot Study

2018 ◽  
Vol 1 (1) ◽  
pp. 39-45
Author(s):  
Maria Yamamoto ◽  
Yukihiro Horie ◽  
Yoshiaki Tagawa ◽  
Susumu Ishida ◽  
Nobuyoshi Kitaichi
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Ophthalmic Solution ◽  
Signs And Symptoms ◽  
Eye Drops ◽  
Subjective Assessments ◽  
Significant Difference ◽  
Related Quality ◽  
Old Females

Purpose: To investigate the preference rates of recently developed eye drops, 3% diquafosol ophthalmic solution and 2% rebamipide ophthalmic suspension, as a randomized clinical trial in patients with dry eye.Methods: Eighteen patients (mean age: 59.7 years old, females: 77.8%) with reduced tear film break-up time (TBUT ? 5 sec) were enrolled in this study. They were treated with either diquafosol or rebamipide for 1 week, and treated for an additional week after switching to the other eye drop. This treatment was repeated one more time. Then, the patients were treated with one of either eye drop for an additional 4 weeks. Patients’ preferences for eye drops were investigated using a questionnaire at the end of 4-week treatment. To confirm the effectiveness of the treatments, objective and subjective assessments including superficial punctate keratopathy (SPK) score, TBUT measurement, and Dry Eye-Related Quality-of-Life Score (DEQS) were performed at baseline, and 4 and 8 weeks.Results: SPK score was improved after treatment (P < 0.05). Patients tended to prefer diquafosol (64.7%) torebamipide (35.4%), however there was no significant difference in two eye drops (P = 0.23). Bitterness was reported significantly more frequently after rebamipide administration (66.7%) than diquafosol administration (5.6%, P < 0.001). The diquafosol bottle was considered “ease to use” by a larger percentage of users (94.1%) as compared to the rebamipide bottle (58.8%, P < 0.05). The effectiveness of the signs and symptoms were similar for both groups at 8 weeks.Conclusions: Diquafosol and Rebamipide were both effective in treating dry eye and 65% of the patients choose Diquafosol. Bitterness after administration and ease to use of the bottles seemed to affect the patients’ preferences for these two eye drops.

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