Why Preservatives
Preservatives are added, as mandated to keep the drug safe and sterile from microbial invasions, bio-degradation and any ambient contaminations. Though preservatives help to keep the formulation sterile over the course of multiple uses, various clinical studies have proved that preservatives also induce ocular surface toxicity and other implications.
Preservatives have not been the desired guests, more so in chronic therapy, while using multiple drugs and in aged patients. Preservatives also have precipitated the discomforts in pre-existing ocular surface diseases such as Conjunctival inflammation, Corneal surface impairment, Conjunctival changes, Ocular surface changes, Epithelial changes, Histological changes, Ocular discomfort, Tear film Instability, Conjunctival inflammation. Hence preservatives have always been undesired guest in an ophthalmic formulation.
The most commonly used preservatives are
- Benzalkonium Chloride (BAK) and its variants
- Polyquaternium
- Stabilised Oxychloro Complex (SOC)
- Sofzia
- Ionic Buffers
The single dose, preservative free, UNIMS, came up as an option, but was not cost effective and also patient friendly. Hence the search has always been for “MULTI DOSE PRESERVATIVE FREE” options, at least in Chronic therapies like Dry Eye & Glaucoma Management.