Glossary

ALA -Alpha Linolenic Acid (An Omega-3 essential fatty acid).

Alpha Lipoic Acid - Water and fat soluble antioxidant.

Anthocyanins - Antioxidants and free radical scavengers.

Astaxanthin (natural) - Retinal carotenoid.

Benzalkonium Chloride - Preservative. 

Boric Acid (Sodium Borate) – Buffer (resists pH change).

Buffer - Resists unwanted changes in pH.

Carbomer - Viscoelastic lubricant. 

Carboxymethylcellulose (Sodium Carboxymethylcellulose/Carmellose sodium) - Low viscosity polymer lubricant with mucomimetic properties.

Chelating agent - Binds metals ions, aiding removal and improves effect of preservative.

Cetrimide – Preservative

CL – Contact Lens

Citrate - Buffer

Dexpanthenol – An osmoprotective - promotes healing.

DHA - Docosahexaenoic Acid (An Omega-3 polyunsaturated fatty acid).

Dimyristoylphosphatidylglycerol - Polar phospholipid surfactant. (Mimics polar lipids in the tear film and decreases tear evaporation).

ECP - (Registered) Eye Care Professional.

EDDB - Eye Drops Database (generally generic comment from database compiler)

EDTA (Disodium Edetate) - Chelating agent.

Electrolytes and Salts (normal tear components) - Electrolytes contribute to osmolarity and act as buffers.

EPA - Eicosapentaenoic  Acid (An Omega-3 polyunsaturated fatty acid).

Food supplements - food supplements cannot be labeled with drug claims but can bear health claims and nutrition claims.

GLA - Gamma Linolenic Acid (An Omega-6 conditionally essential fatty acid).

Glycerin – Increased water retention. May act as an osmoprotective.

GMC - General Medical Council

GOC - General Optical Council

HCP - (Registered) Health Care Professional

Hx/HX - History (as in history of allergic reactions)

Hydroxypropyl guar (HP-Guar) - Viscoelastic lubricant. 

Hypertonic – A higher solute concentration (osmolarity) than normal tears.

Hypotonic - A lower solute concentration (osmolarity) than normal tears. 

Hypromellose (HPMC) - Low viscosity polymer lubricant.

IFU - IFU stands for Information For User (also known as Package Leaflet or PL) and is the leaflet that is included in the pack. The IFU is written by the manufacturing company and is a user-friendly version of the Summary of Product Characteristics, if there is one. It fulfils a similar use to a PIL.

Isotonic - The same solute concentration (osmolarity) as normal tears, no net movement of water between cells.

Keratoconjunctivitis Sicca - Dryness of the cornea and conjunctiva.

Liquid paraffin - High viscosity polymer lubricant.

Legal category - Every medicine has a legal category. POM means prescription only medicine - Pxs can only be supplied the medicine on prescription. P means pharmacy - Pxs can only be supplied the medicine from a retail pharmacy/(specified medicines may be supplied under the supervision of an optometrist). GSL means general sales list - you can buy the medicine without a pharmacist, for example in a supermarket. CE Mark is used on devices.

Lutein - Retinal Carotenoid.

Magnesium - Electrolyte.

Mineral oil - Lipid.

N/A - Not applicable (Many products in this database are not legally defined as medicines, so would not fall in the three legal categories: GSL, P or POM, neither would they be classed as Food Supplements).  As time goes by this database will 'tidy' the classification of products from GSL to N/A.

Non-Newtonian - In a non-Newtonian fluid, the relation between the shear stress and the shear rate is different and can even be time-dependent (Time Dependent Viscosity). Therefore, a constant coefficient of viscosity cannot be defined.

Ocupure – A vanishing preservative, which breaks down into water, oxygen and sodium chloride on light exposure.

Osmolarity - The measure of solute concentration per unit volume of solvent. 

Osmoprotective – The ability to resist cellular damage/death due to abnormal osmolarity. 

Oxyd – A vanishing preservative, which turns to water, oxygen and sodium chloride on contact with the eye.

P medicine - see Legal category.

Phenoxyethanol - Found in eye sprays. A vanishing preservative which evaporates from the aerosol state.

Phosphate - Electrolyte.

Phospholipid - Lipid layer stabiliser 

PIL - PIL stands for Patient Information Leaflet (known as Package Leaflet or PL) and is the leaflet that is included in the pack with a medicine. The PIL is written by the pharmaceutical company and is a patient-friendly version of the Summary of Product Characteristics. All PILs are checked and approved by the UK or European medicines licensing agency.

Polyethylene glycol (PEG) - Lubricant.

Polyhexanide (Polyhexamethylene biguanide/PHMB) - Preservative.

Polyquad (Polidronium chloride/Polyquaternium 1) - Preservative.

Polyvinyl alcohol (PVA) - Low viscosity polymer lubricant.

POM - see Legal category.

Potassium - Electrolyte.

Povidone (Polyvinylpyrrolidone/PVP) - Low viscosity polymer lubricant.

Preservative – A substance that retards microbial growth.

Preservative Free – Free from any form of artificial preservative, including vanishing preservatives.

Propylene glycol - Lubricant.

Purite - Vanishing preservative which breaks down into water, oxygen and sodium chloride when exposed to light.

Pt(s)/Px(s)/PX(S) – Patient.

Residence time – Time product remains on the ocular surface.

Rx/RX – Prescription.

Sodium - Electrolyte.

Sodium Hyaluronate (Hyualuronic acid) - Viscoelastic lubricant.

Sorbitol A. - Optimises viscosity to reduce blur on instillation.

Soy bean oil - Source of phospholipids.

Soy lecithin – Contains phospholipid.

SPC/SmPC - SPC, or SmPC, stands for Summary of Product Characteristics. The SPC is used by healthcare professionals, such as doctors, nurses and pharmacists, and explains how to use and prescribe a medicine. SPCs are written and updated by pharmaceutical companies and are based on their research and product knowledge. The SPC is then checked and approved by the UK or European medicines licensing agency. The IFU fulfils a similar function in non-medicines.

Stabilising agents - A chemical that tends to inhibit reactions between other chemicals.

Surfactants - A molecule that contains both a water insoluble component and a water soluble component enabling them to bind together, Serve as cleaners and wetting agents.

Tonicity - The osmotic pressure gradient of two solutions (tears and cell contents) separated by a semi-permeable membrane (the cell membrane).

Trehalose - An osmoprotective disaccharide.

Triglycerides - Lipids

Trometamol – Buffer

Tx/TX – Treatment.

Vanishing preservative - Preserves the product in the bottle but is not present in the eye.

Viscoelastic – (Non-Newtonian properties) Lubricant exhibiting both viscous and elastic behaviour when deformed.

Viscosity - A fluids resistance to flow. Higher viscosity equals longer residence time on the eye, but more tendency to blur vision. To compare water has a viscosity of 1.0cps at 25 degrees Celsius. 

Vitamin A - An antioxidant. May promote corneal healing.

Vitamin B12 - May protect from oxidative stress.

Vitamin E - An antioxidant. May also help stabilise the lipid layer.

White soft paraffin - High viscosity polymer lubricant.

Xanthan gum - Polymer. Prolongs residence time.

Zeaxanthin - Retinal carotenoid. Zinc also acts as an antimicrobial.

Zinc - Cellular membrane stabiliser.

Zinc-hyaluronate - Zinc bound to hyaluronic acid, forming a mechanical barrier.

 

Search Tips:

The search is not case sensitive.

I have tried to avoid hyphens, so a product produced and labelled Preservative-Free is Preservative Free in the database.

You can search for words, or parts of words, do not enter commas, full stops etc, just the word itself. For instance to search for Preservative Free listed products, a search for the word free will identify all the products you want, do double check your results if using this type of shorthand in your search, as the word free may be used in a different context on the product page ie; phosphate free . Another example of many I could use; if you want to identify products that are osmoprotective, a search for osmop will identify all the products you want. 

The search facility is intended to narrow down products that fulfil your criteria, it is not intended to give a perfect product match, so the narrowed down product pages that it finds should be checked by the user. If you have spare time entering in search words will enable you to get to know the database better.

Ticking the 'Contact Lens Use?' box will identify all products that have their use with contact lenses as their 'Prime Indication' or can be used with contact lenses 'If required'.

If you do see any errors or omissions in the glossary or search tips, please contact us, your input would be gratefully received.