Hypromellose is a highly viscous polymer with a number of applications. It is very widely used in the medical community, and it also appears as a thickener in some types of foods. This polymer is considered nontoxic, although it can be flammable in some settings, and it is produced by a number of companies, some of which specialize in production for very specific applications.
The full name of this polymer is hydroxypropyl methylcellulose; hypromellose is a shortened version of this longer chemical name. The very high viscosity of hypromellose makes it ideally suited to use in ocular preparations which are designed to address dry eye. Some artificial tears contain hypromellose, and the polymer is also used in some types of eye surgeries to keep the eye lubricated. As a lubricant, it can both soothe the eye if it is irritated, and create a barrier to protect the eye from additional irritation. Products with hypromellose can be found over the counter in some regions, and are also available by prescription.
In addition to being used in the eyes, this compound is also used for oral drug delivery in some situations. Hypromellose can control the rate of drug delivery, ensuring that the body is not flooded with a medication, and it can act as an inert thickener in oral medications which will improve texture without compromising the function of the active pharmaceutical compounds in the drug. Some tablet coatings include the compound, and it works as a binder for certain types of medications.
This compound is also used in foods to thicken, suspend, or emulsify ingredients. It is vegetarian, which makes it an alternative to gelatin in foods which are meant to be safe for vegetarians. Hypromellose also appears in cosmetics, paints, adhesives, and some cleaning products. In construction materials, the moisture retaining properties of the compound may be turned to advantage, although they can also become problematic if the compound is not stored and handled properly, as it can increase in weight as it picks up water.
In its pure form, this compound is a powder or granule, which can be mixed up in an aqueous solution if necessary for a particular application. Processing techniques used to make this compound can vary, depending on how it is going to be used. It is often sold and transported in the powder form, with manufacturers who use it turning it into a solution on site if needed. Transporting it while dry reduces transport costs and makes it easier to handle.