The impact of artificial tears containing hydroxypropyl guar on mucous layer

Safe and Effective Management of Dry Eye Symptoms with Hydroxypropyl Guar and Hyaluronic Acid Dual-Polymer Lubricating Eye Drops: A Review of Preclinical and Clinical Studies

Dry eye disease (DED) is a chronic ocular surface disorder often characterized by decreased tear production and rapid tear evaporation that affect tear film stability and homeostasis. The common symptoms of DED include ocular discomfort, visual disturbances, dryness, and itching. Artificial tears are the mainstay of DED management and supplement one or more layers of the tear film. Artificial tear drops are available as a combination of viscosity-enhancing agents (demulcents/lubricants), humectants, and buffers either with or without preservatives. Artificial tears, as a combination of components (polymers/demulcents/viscosity-enhancing agents), can provide synergistic action compared with a single component for the management of multifactorial signs and symptoms of DED. This review describes the formulation components, physicochemical properties, mechanism of action, and summary of preclinical and clinical evidence on the hydroxypropyl guar-hyaluronic acid (HPG-HA) dual-polymer lubricant eye drops (SYSTANE™ HYDRATION). The dual-polymer eye drops consist of dual demulcents (propylene glycol and polyethylene glycol 400) and the polymers hydroxypropyl guar (HPG) and hyaluronic acid (HA). When instilled on the ocular surface, HPG forms a cross-linked gel matrix with borate ions that prolongs the retention of demulcents, thus providing long-lasting lubrication and ocular surface protection. Additionally, HA stabilizes the tear film, increases corneal wettability, and reduces friction during blinks due to its hygroscopic and viscoelastic properties. Preclinical evidence demonstrates that HPG HA dual-polymer lubricant eye drops provide protection against desiccation by cell hydration and surface retention, cell barrier protection, prolonged lubrication, and promotion of corneal re-epithelialization. Clinical scientific evidence demonstrates that HPG HA dual-polymer lubricant eye drops are safe and effective in the management of DED. Specifically, they reduce the signs and symptoms of DED, reduce dry eye symptoms post-cataract surgery, and improve tear film quality in healthy eyes.

Propylene Glycol and Hydroxypropyl Guar Nanoemulsion - Safe and Effective Lubricant Eye Drops in the Management of Dry Eye Disease

Dry eye disease (DED) is a chronic condition of the ocular surface characterized by a loss of the tear film homeostasis and accompanied by symptoms such as eye discomfort and visual disturbances. DED is classified as aqueous deficient dry eye (ADDE), evaporative dry eye (EDE), and mixed dry eye etiologies. The mainstay treatment in the management of DED is artificial tear drops or lubricant eye drops that replenish the aqueous and/or lipid layer of the tear film. These are available as both lipid-based and non-lipid-based formulations, with/without preservatives. Lipid-based lubricant eye drops can stabilize the tear film lipid layer, reduce tear evaporation, and improve signs of EDE. In this review, we present the formulation components, mechanism of action, and summary of preclinical and clinical evidence on a lipid-based formulation - propylene glycol-hydroxypropyl guar (PG-HPG) nanoemulsion lubricant eye drops (Systane^TM Complete). These eye drops consist of the demulcent (lubricant), PG (0.6%). HPG forms a soft, thin, cross-linked in situ gel matrix with borate ions, when exposed to the tear film, which prolongs lubricant retention and provides ocular surface protection. Dimyristoyl phosphatidyl glycerol, an anionic phospholipid, helps in replenishing the lipid layer of the tear film. Moreover, the nanoemulsion formulation serves as a depot for delivery of dimyristoyl phosphatidyl glycerol to enhance ocular surface coverage. Preclinical and clinical evidence demonstrate that PG-HPG nanoemulsion lubricant eye drops are safe and effective in providing temporary relief of symptoms of DED, regardless of its subtypes. Specifically, it provides sustained reduction in dry eye symptoms, improves tear film stability/lipid layer grade, and improves ocular surface characteristics.

A randomized multicenter clinical evaluation of sequential application of 0.3% and 0.15% hyaluronic acid for treatment of dry eye

PURPOSE

We report the clinical efficacy of sequential applications of 0.3% and 0.15% unpreserved hyaluronic acid (HA) for the treatment of dry eye disease (DED).

STUDY DESIGN

Randomized clinical trial.

METHODS

Patients over 19 years of age with DED level 2 or higher, corneal fluorescein staining (CFS) score > 1, and tear break-up time (TBUT) < 10 s were included. Seventy-six patients were randomly assigned to the 0.15% HA group, 0.3% HA group, or combination group. Each group applied two drops of 0.15% or 0.3% HA, or a single drop of both 0.3% and 0.15% HA. Patients were evaluated using the ocular surface disease index (OSDI), CFS and conjunctival fluorescein stain score, TBUT, and blurring/discomfort after application at baseline, 4 weeks, and 8 weeks.

RESULTS

The combination group had the greatest improvement in CFS score from baseline to 8 weeks, compared with the 0.15% and 0.3% HA group (p < 0.001). The combined CFS-OSDI responder rates of the combination group (CFS score = 0 and OSDI ≥ 50% improvement at 8 weeks) were significantly higher than those of the 0.15% and 0.3% groups (p = 0.037). At 4 and 8 weeks, blurring after application in both the 0.3% and combination groups was significantly higher than in the 0.15% group, despite no difference between the 0.3% and combination groups. There were no differences in CFS and conjunctival staining score, TBUT, or OSDI within the three groups at baseline, 4 weeks, and 8 weeks.

CONCLUSIONS

Sequential application of 0.3% and 0.15% HA improved symptoms/signs in moderate to severe DED patients.

Therapie des Trockenen Auges

Die Therapie des Trockenen Auges stellt eine schwierige Aufgabe für den behandelnden Augenarzt dar. Fortschritte in unserem Verständnis der Risikofaktoren, der Ätiologie und Pathophysiologie des Trockenen Auges haben zu einer Weiterentwicklung der Behandlungsstrategien geführt. Vor Beginn der Therapie ist die korrekte Zuordnung in eine wässrig-muzinöse Tränenfilmdysfunktion (Mindersekretion), in eine lipidbedingte Tränenfilmdysfunktion (hyperevaporative Form durch eine abnormen Meibom-Drüsen-Physiologie) oder in eine variable Kombination wichtig. Unter Berücksichtigung aktueller Empfehlungen der DOG, des BVA und des TFOS DEWS II Unterausschusses wurde ein Behandlungsalgorithmus abgeleitet, der ein schrittweises Vorgehen je nach Schweregrad der Erkrankung darstellt.

A Decade of Effective Dry Eye Disease Management with Systane Ultra (Polyethylene Glycol/Propylene Glycol with Hydroxypropyl Guar) Lubricant Eye Drops

Dry eye disease (DED) is a multifactorial ocular condition characterized by a loss of homeostasis of the tear film resulting in ocular symptoms of discomfort, irritation, and visual disturbance, all of which significantly impact the patients’ social and occupational quality of life. While management of DED depends on the severity of symptoms and signs, use of artificial tear products (ATPs) that replace or supplement the deficient natural tear film is the mainstay treatment option. In this review, we present a decade of evidence on Systane Ultra^® (polyethylene glycol [PEG]/propylene glycol [PG] with hydroxypropyl guar [HP guar]) in effectively managing DED. The active demulcents in Systane Ultra^®—PEG, PG, along with HP guar gelling technology—provide optimal ocular surface protection and lubrication to heal damaged areas of the cornea caused by DED and, therefore, are recommended for patients with both aqueous and/or mucin layer deficiencies. Over the years, several clinical studies have shown that PEG/PG with HP guar provides long-lasting relief from dry eye and has often been chosen as a standard or comparator against other ATPs. Here, we describe the salient features of PEG/PG with HP guar—its constituents and their mechanisms of action. Furthermore, we summarize results from a systematic literature search that identified 23 relevant publications further emphasizing on the effectiveness and safety of PEG/PG with HP guar in alleviating the signs and symptoms of DED.

Self-emulsifying drug delivery system: Mucus permeation and innovative quantification technologies

Mucus is a dynamic barrier which covers and protects the underlying mucosal epithelial membrane against bacteria and foreign particles. This protection mechanism extends to include therapeutic macromolecules and nanoparticles (NPs) through trapping of these particles. Mucus is not only a physical barrier that limiting particles movements based on their sizes but it selectively binds with particles through both hydrophilic and lipophilic interactions. Therefore, nano-carriers for mucosal delivery should be designed to eliminate entrapment by the mucus barrier. For this reason, different strategies have been approached for both solid nano-carriers and liquid core nano-carriers to synthesise muco-diffusive nano-carrier. Among these nano-strategies, Self-Emulsifying Drug Delivery System (SEDDS) was recognised as very promising nano-carrier for mucus delivery. The system was introduced to enhance the dissolution and bioavailability of orally administered insoluble drugs. SEDDS has shown high stability against intestinal enzymatic activity and more importantly, relatively rapid permeation characteristics across mucus barrier. The high diffusivity of SEDDS has been tested using various in vitro measurement techniques including both bulk and individual measurement of droplets diffusion within mucus. The selection and processing of an optimum in vitro technique is of great importance to avoid misinterpretation of the diffusivity of SEDDS through mucus barrier. In conclusion, SEDDS is a system with high capacity to diffuse through intestinal mucus even though this system has not been studied to the same extent as solid nano-carriers.

Preclinical Evaluation of a New Hydroxypropyl-Guar Phospholipid Nanoemulsion-Based Artificial Tear Formulation in Models of Corneal Epithelium

PURPOSE

To evaluate the effect of hydroxypropyl-guar anionic phospholipid nanoemulsion (HP-guar nanoemulsion), a new artificial tear formulation for treatment of dry eye disease (DED), in corneal epithelium models.

METHODS

Cultured human corneal epithelial cells were used to assess (1) hydration protection and hydration retention protection against desiccation, and (2) cell recovery after benzalkonium chloride (BAC) damage. Corneal epithelium permeability was measured by 5,6-carboxyfluorescein (CF) uptake in intact rabbit eyes. Lubricity was determined using simulated blinking in bovine pericardium-pericardium tribological experiments; elastic filament strength was measured using an extensional rheometer. Comparator arms included vehicle/control and the microemulsion [Systane^® Balance (SYSB)].

RESULTS

Cell hydration protection was 39.5%, 7.1%, and -0.1%, and surface hydration retention was 32.6%, 11.0%, and -1.2% with HP-guar nanoemulsion, SYSB, and vehicle, respectively, after desiccation. After 48 h, cell recovery from BAC exposure (relative fluorescence units ± SD) was faster with HP-guar nanoemulsion treatment (2.66 ± 0.2) than SYSB (2.76 ± 0.2) and vehicle (3.11 ± 0.4). The CF permeability (ng CF/g) decreased in rabbit cornea treated with HP-guar nanoemulsion (9.6 ± 2.3) than those with SYSB (13.12 ± 2.8) or BAC-exposed cornea (22.6 ± 5.1). HP-guar nanoemulsion demonstrated greater lubricity and polymer filament break-up time than SYSB and vehicle. In all assessments, HP-guar nanoemulsion showed significant improvement versus vehicle/control (P < 0.05); outcomes were better with HP-guar nanoemulsion versus microemulsion.

CONCLUSIONS

The HP-guar nanoemulsion promotes greater moisture retention, protection, improved cell barrier function, and increased elastic filament strength in corneal epithelium models. The potential clinical benefits of HP-guar nanoemulsion needs to be evaluated in patients with DED, in future studies.

Tear osmolarity changes after use of hydroxypropyl-guar-based lubricating eye drops

Purpose

To evaluate tear osmolarity after using a hydroxypropyl-guar (HP-guar)-based lubricating eye drop four times daily (QID) for 3 weeks.

Methods

Thirty-one participants with dry eye disease (Ocular Surface Disease Index [OSDI] score ≥20 and tear osmolarity ≥300 mOsm/L in at least one eye) were enrolled in this prospective, dispensing, non-randomized study involving a baseline visit and 3-week follow-up. Tear osmolarity, non-invasive tear break up time (NITBUT), conjunctival hyperemia, corneal and conjunctival staining were determined at baseline. Participants were instructed to instill one drop of a HP-guar-based drop QID in each eye for 3 weeks. At the follow-up visit, the symptoms and ocular surface parameters were reassessed. At this visit, one HP-guar drop was instilled into each eye and osmolarity was measured after 15 minutes, to examine short-term changes in osmolarity.

Results

Twenty-eight participants completed the study (5M, 23F; median age 54 yrs, range 25-83 yrs). At baseline, mean OSDI score was 44.9±15.2 and mean osmolarities were 314.63±11.9/306.6±10.1 mOsm/L (worst eye [WE]/better eye [BE]). After 3 weeks, mean osmolarity reduced to 307.7±15.7/303.9±11.3 mOsm/L (WE/BE; p<0.05 and p=0.228, respectively) and mean OSDI scores reduced to 28.3±17.0 (p<0.01). A significant reduction in osmolarity was observed 15 minutes after instilling the lubricating drop (p<0.05 WE, p=0.09 BE). Significant improvements in central corneal staining (p<0.05 OU) and NITBUT (p<0.05 WE only) were observed. Reductions in conjunctival staining and hyperemia were observed, but were not significant (p>0.05).

Conclusions

A significant reduction in tear osmolarity and improvements in dry eye symptoms, corneal staining, and NITBUT were observed after 3 weeks of QID use of a HP-guar-based lubricant drop. A decrease in osmolarity was also demonstrated 15 minutes after drop instillation.

Modulation of HLA-DR in dry eye patients following 30 days of treatment with a lubricant eyedrop solution

Purpose

To determine the changes in dry eye disease (DED) severity and the percentage of cells expressing HLA-DR on the ocular surface following treatment with lubricant eyedrops containing polyethylene glycol and propylene glycol (PEG/PG) and the gelling agent hydroxypropyl guar (HP-Guar).

Patients and methods

Nineteen patients with DED used PEG/PG + HP-Guar eyedrops four times per day for 30 days. Assessments included DED severity (Ocular Surface Disease Index [OSDI], corneal staining, conjunctival staining, tear film break-up time [TFBUT], and Schirmer testing) and impression cytology of the conjunctiva with masked flow cytometry at baseline and at 30 days.

Results

There was a significant decrease in corneal staining (P<0.01), OSDI (P=0.02), and TFBUT (P<0.01) following treatment with PEG/PG + HP-Guar. Results from flow cytometry revealed a significant decrease in cells expressing HLA-DR (P=0.02).

Conclusion

Treatment with PEG/PG + HP-Guar eyedrops showed improvement in dry eye severity and reduction in surface inflammation as indicated by a reduction in HLA-DR expression.