Why Preservative-Free Eye Drops?

Why Preservative-Free Eye Drops?

We use eye drops daily not only for comfort but to enhanced visual performance, protection and to get dry eye relief. Why not choose a drop that helps us perform the best at work, at play, and at home. Dry eye has become one of the most common conditions facing our today's society due to increasing demand of screen work. Our eyes are so important, so why not treat them right.

Studies have shown that preservatives can destroy the natural tear film and cause damage to cell tissues, which makes it intolerable for long-term use.

Most older preservative-containing eye drops recommend disposal after only 30 days from opening. Meanwhile, preservative-free eye drops can last far longer 3, 6 and some up to 12 months from opening due to their nature of their bottle to keep drops clean by using separate compartments to prevent back-flow. This can significantly make your drops last longer while using something more safe for your eyes.



The most common formulations of buffer systems used in eye drops are phosphate, citrate, borate, or Tris-HCL (Tris). Ideally, buffer systems help maintain the pH to help maintain the composition of the formulation to extend shelf life and mimic the natural tear film. The average physiological pH of lacrimal fluid is 7.4 (ranges from 6.5-7.6).

Phosphate buffers are the most widely used buffer since it has excellent capabilities at keeping pH levels neutral. In addition, as phosphate exists naturally on the surface of the eye, it is seen as a safe buffer. Selective case reports in rabbits with corneal abrasions noted that extremely high-levels of phosphate can bind to calcium released from damaged cells (epithelial keratopathy), which can form insoluble calcium deposits on the surface of the eye (corneal calcification). While other studies show risks associated with this is in humans is rather low without pre-existing corneal defects, this is particularly important to consider when using eye drops after corneal injury and post-laser surgery for healing. In a healthy eye, phosphate buffers are safe. Newer eye drops tend to use a citrate, borate, or Tris buffer to maintain a safe pH solution for the eyes; the latter being the least cytotoxic to cellular tissues and shows highest cell viability.

Benzalkonium chloride (BAK) is a preservative that is widely used in eye drops since the 1940s. Almost 70% of all eye drops still use BAK. It is effective as a preservative since its good at killing microorganisms. It acts as a detergent to lysing cell membranes. Recent studies have shown that high concentrations of BAK can be toxic to ocular tissues by causing apoptotic response in corneal tissues. However, there are also many studies that show that BAK at various concentrations does not affect corneal tissues and is no more toxic than other preservatives found in eye drops. Patients who have long standing symptoms of dry eye should consider drops that are preservative-free.

Hyaluronic acid (HA) is a natural occurring substance in nature (a glycosaminoglycan to be specific). Sodium hyaluronate is the salt form of HA, which is a more stable compound used in eye drop formulation. HA binds to water, prevents dehydration, and is highly biocompatible as it is naturally found in high concentrations in the eye. Studies have shown HA improves optical quality, promotes wound healing by stimulating epithelial migration, and protects corneal epithelial damage. This is great for those who have dry eyes, working in front of computer screens, and especially those recovering from surgery. 


Our Promise

We pride our itself in sourcing only preservative-free eye drops for your peace of mind knowing you are using only healthy eyes drops that speed up your recovery and dry eye problems. We do the research so you don't have to worry. See our PuffinBox Kits customized care kits for Recovery, Starters, Couples, and Nutrition kits to care for your eyes shipped directly to your doorstep. 

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