Hypromellose - Eye Lube!!!

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Without letting the title mislead you let's talk about Hypromellose - the main component of eye-drops¹. Why should anyone care? Well it is essential to majority of us in Calgary. With the cold winds and dry climate without eye-drops we would all look like Crazy Eyes from Orange is the New Black, also allergies!! So what is Hypromellose? It's a massive compound with an IUPAC name containing 60 characters and 20 numbers². It's also called Hydroxypropyl methylcellulose². From the name itself we see that it is a product of cellulose³. In fact it is formed by processing cellulose pulp with caustic soda and CH₃Cl and C₃H₆O. Thus we get the ‘methyl-’ and ‘proply-’ groups³. It’s highly non – toxic except when taken in exceptionally large quantities⁴ (I’m talking gigantic!).

The compound has many wonderful qualities like its odorless⁵, has a high melting point⁶ and is exceptionally viscous⁵. Thus it is good for the eyes since it form a film protecting the moisture of the eye. The other alternative to hypromellose is gelatin⁷, for me the ethical option is hypromellose then some poor animal’s bone marrow. Historically hypromellose has been used for eye procedures for 10 years however the only case of ‘Hypormellose allergy’ was detected in a lone Danish man⁸ – who suffered a severe allergic reaction when he went for cataract surgery – both times. With exception to this one case hypromellose is an awesome chemical and used as a placebo in most eye experiments⁹. Other than eye-drops hypromellose is used as a food additive¹, thickener¹, and filler in supplements¹⁰, adhesives¹ and in cement¹. For all the gluten free people reading this…say hello to your gluten¹¹!!

In conclusion, hypromellose is a good chemical that won’t harm you (except that Danish man) and in whose presence there will never be a dry eye!

References

¹Burdock, George A. Safety assessment of hydroxypropyl methylcellulose as a food ingredient. Food Chem. Toxicol. 2007, 45(12), 2341-2351. Google Scholar library.mtroyal.ca:2091/science/article/pii/S027869150700261X?via%3Dihub#tbl3 (accessed March 2^nd, 2016).

²Hypromellose, 2012. PUBCHEM. https://pubchem.ncbi.nlm.nih.gov/compound/57503849#section=Top (accessed March 1, 2016). 

³Li, Chi L., et al. The use of hypromellose in oral drug delivery. Trans. Br. Pharm. Conf [Online]. 2005, 57(5), 533-546. Google Scholar, http://depa.fquim.unam.mx/amyd/archivero/HPMCenliberacionoral_7272.pdf (accessed Apr 29, 2016).

⁴Osol, A, et al. Remington’s Pharmaceutical Sciences, 15th Ed, Macl Publishing Co: Easton, Pennsylvania, 1975, pp. 1244.

⁵Budavari, S. The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Merck and Co., Inc: Whitehouse Station, NJ, 1996; pp. 1033.

⁶Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. John Wiley and Sons: New York, NY, 1991; pp. 554.

⁷Bouyer, Eléonore, et al. Proteins, polysaccharides, and their complexes used as stabilizers for emulsions: alternatives to synthetic surfactants in the pharmaceutical field?.. Int. J. Pharm. [Online]. 2012, 436 (1), 359-378. Google Scholar https://www.researchgate.net/profile/Ghozlene_Mekhloufi/publication/228114201_Proteins_polysaccharides_and_their_complexes_used_as_stabilizers_for_emulsions_alternatives_to_synthetic_surfactants_in_the_pharmaceutical_field._Int_J_Pharmaceutics/links/02bfe51126829146b8000000.pdf (accessed February 25th, 2016).

⁸Munk, Sofie J., et al. Two episodes of anaphylaxis following exposure to hydroxypropyl methylcellulose during cataract surgery. J. Cataract Refractive Surg. 2013, 39(6), 948-951. Google Scholar library.mtroyal.ca:2091/science/article/pii/S027869150700261X?via%3Dihub (accessed March 2^nd, 2016).

⁹Gupta, A., et al. Effect of betaxolol on the retinal circulation in eyes with ocular hypertension: a pilot study.  Eye. [Online]. 1994, 8 (6), 668-671. Google Scholar http://www.nature.com/eye/journal/v8/n6/pdf/eye1994165a.pdf (accessed February 28th, 2016)

¹⁰Dangerous (and Common) Vitamin Fillers You Must Avoid. http://draxe.com/4-dangerous-and-common-vitamin-fillers-you-must-avoid/ (accessed March 2016)

¹¹Wood, M. Inventing New Oat and Barley Breads, 2010. United States Department of Agriculture. http://www.ars.usda.gov/is/pr/2010/100225.htm (accessed March 2^nd, 2016)