Cofresh

Uses

It is used for the symptomatic relief of burning, irritation, and discomfort due to dryness of the eye or exposure to wind or sun. It is also used for the treatment of keratoconjunctivitis sicca.

Cofresh is also used to associated treatment for these conditions: Dry Eyes, Ocular Discomfort, Ocular IrritationConstipation, Dry Eyes

How Cofresh works

Promotes corneal wetting by the stabilization and thickening the precorneal tear film and prolonging the tear film breakdown time, which is usually shortened in dry eye conditions. Hypromellose also acts to lubricate and protect the eye .

The surface active properties of the vehicles found in artificial tears solutions act to stabilize the tear film and increase tear viscosity to prevent delay tear evaporation and delay tear drainage .

In the intact eye, the corneal surface is moistened primarily by the mucin that is produced in the conjunctiva. Mucin is adsorbed on the corneal surface and forms a hydrophilic surface. This creates a moisture barrier. In the typical dry eye, and particularly in case of mucin deficiency, the application of artificial tear fluid is highly recommended. Both its surface activity and its adsorptive capacity make hypromellose optimal for this use. Hypromellose has a physical-chemical action and leads to, in an aqueous solution, a reduced surface tension as well as an increased level of viscosity. Hypromellose adheres well to the cornea and conjunctiva and provides ample moisture. Irritation symptoms caused by blinking, which occur in the case of tear fluid deficiency, are therefore decreased and symptoms of epithelial desiccation are also alleviated .

PEG, depending on molecular weight, has various mechanisms of action , , , . For the purpose of Peg-400, the mechanism of action on the eye tissues will be the primary focus of discussion.

PEG-400 is considered a lacrimomimetic, or a synthetic ocular lubricant that improves one or more components of the lacrimal film by augmenting the tear volume and stability and by protecting the eye surface against desiccation . Hydroxypropyl-guar (HPG) is used along with polyethylene glycol 400 (PEG) and propylene glycol (PG) as a gelling agent that conforms to abnormalities of the tear film and existing irregularities on the ocular surface .

PEG provides lubrication and acts as a surfactant by coating the eye and interacting with propylene glycol and other solutions that help to act as surfactants on the eye mucosa . This allows for long-lasting, soothing effects .

Recent studies involving nanoparticle drug delivery have demonstrated that PEG can achieve sustained drug delivery. The delivery of drugs to mucosal surfaces is a significant challenge due to the presence of the protective mucus layer that acts to trap and quickly remove foreign particles. Nanoparticles designed to rapidly cross mucosal barriers (mucus-penetrating particles, “MPP”) have proven promising for augmenting drug distribution, and efficacy at various mucosal surfaces. Mucus- penetrating particles are heavily coated with polyethylene glycol (PEG), protecting the nanoparticle core from adhesion with mucus .

Polyethylene glycol, when free in solution, may also demonstrate attraction to the surfaces of various types of vesicles, cells or macromolecules, leading to polymer adsorption and subsequently either a repulsion or to an attraction, via bridging, of the surfaces or vesicles—again strongly depending on the temperature, molecular weight, and concentration of the polyethylene glycol. Low molecular weight polyethylene glycol (such as PEG-400) generally promotes cells or vesicles to adhere (depletion attraction), high molecular weight polyethylene glycol causes them to repel .

Dosage

Cofresh dosage

1 to 2 drops in the affected eye(s) up to 4 times daily.

Side Effects

Occasionally mild, transient burning or sticky sensation and very rarely irritation or hypersensitivity reactions reported. Blurred vision after application may occur.

Toxicity

LD 50 (Rat): > 5 g/kg .

Hypromellose is considered low toxicity to non-toxic .

Adverse events may include blurred vision and contact dermatitis . Hypersensitivity and intolerance reactions may occur (for example, eye burning, pain, increased lacrimation, a sensation of foreign body, conjunctival hyperemia, eyelid swelling, pruritus). The stickiness sensation of the eyelids, the decreased sense of smell, photosensitivity .

PEG of different molecular weights by a range of routes has been studied extensively, and has not led to any major toxicities, and signs/symptoms of toxicity that do occur are only observed at a much higher than therapeutic dose .

LD50 = 157000 mg/kg, intragastric, guinea pigs LD50 = 28915 mg/kg, intragastric, mice, rats LD50 = 9708 mg/kg, intra-abdominal, rats LD50= 7312 mg/kg, intravenous, rats

Precaution

Remove contact lenses before using this drug. Do not use if this solution changes color or becomes cloudy. Don't touch tip of container to any surface to avoid contamination and replace cap after each use.

Interaction

If several medicines are to be administered to the eye, there should be an interval of at least 5 minutes between each application.

Elimination Route

Not systemically absorbed .

PEG has low toxicity profile with an absorption of less than 0.5% .

Topical absorption of PEG occurs and, demonstrates a molecular weight dependence similar to that of PEG given orally. Absorption by this route is likely to be poor .

Half Life

Great than 24h .

Clearance

In mice, lease than 12.

Elimination Route

Human excretion studies have demonstrated that 86% and 96% of PEG1000 and 6000 were excreted in the urine 12 h after intravenous administration. Specific data on PEG-400 are not available . In rats, urine PEG undergoes biliary excretion, and this process is depending on molecular weight, with hepatic clearance reaching a minimum at about 50 kDa molecular mass (in mouse).

Pregnancy & Breastfeeding use

Pregnancy Category- Not Classified. FDA has not yet classified the drug into a specified pregnancy category.

Contraindication

This eye drops is contraindicated in patients with known hypersensitivity to any ingredient of the product.

Acute Overdose

No case of overdose has been reported.

Storage Condition

Store at room temperature. It is desirable that the contents should not be used more than 4 weeks after first opening of the bottle.

Innovators Monograph

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