Views: 281 Author: Vickey Publish Time: 2023-06-01 Origin: Site
As a short form of hydroxypropyl methylcellulose (HPMC), hypromellose (INN), also known as hydroxypropyl methylcellulose, is a semi-synthetic, inert, viscoelastic polymer utilized in eye drops as well as an excipient and controlled-delivery component in oral medications. As a food ingredient, hypromellose functions as a thickening, suspending, and emulsifying agent as well as a substitute for animal gelatin.
Hypromellose is a solid that has an appearance ranging from slightly off-white to beige powder and may be made into granules. When the substance is dissolved in water, colloids are created. This non-toxic component can react violently with oxidizing chemicals and is flammable.
Like methylcellulose, hypromellose has a heat gelation characteristic in an aqueous solution. In other words, when a solution reaches a certain temperature, it congeals into a semi-flexible, non-flowable lump.
The concentration of HPMC in solution and the concentration of the methoxy group inside the HPMC molecule (which in turn relies on both the degree of substitution of the methoxy group and the molar substitution) are often inversely linked to this crucial (congealing) temperature.
In other words, the critical temperature decreases as the methoxy group concentration increases. However, the degree of rigidity or viscosity of the resultant mass is inversely proportional to the methoxy group concentration (the greater the concentration, the more rigid or viscous the resulting mass).
There are many fields of application for hypromellose, including:
Scientists from the Agricultural Research Service are examining the possibility of replacing gluten in all-oat and other grain breads with HPMC, a substance generated from plants. The gluten found in wheat, rye, and barley is missing (or only small amounts of gluten are present) in oats and other grains. Similar to gluten, HPMC may also act as a trap for yeast-created air bubbles in bread dough, enabling the loaf to rise.
Typically, HPMC is utilized as a rheology modifier and water retention agent in building materials like tile adhesives and renders.
HPMC (hydroethyl methyl cellulose) and HEMC (hydroxyethyl methyl cellulose) are quite comparable in terms of functionality.
As an alternative to tear film that is semi-synthetic, hypromellose solutions were patented. Its molecular structure is based on a very water-soluble basic celluloid compound. According to reports, the good water solubility of celluloid contributes to its optical clarity after application. A hypromellose solution operates to swell and absorb water when applied, increasing the tear film's thickness.
Therefore, hypromellose augmentation prolongs the lubricant's stay on the cornea, which should reduce eye discomfort, particularly in dry situations like the home or workplace. This polymer's molecular structure includes beta-linked D-glucose units, which maintain their metabolic integrity for days or weeks.
Due to semi-synthetic production procedures, hypromellose is somewhat more expensive to make than gelatin since it is a vegetarian alternative.In addition to being widely available over the counter in many different forms, hypromellose 2% solution has also been shown to be utilized during surgery to help preserve the cornea and during orbital surgery.
Hypromellose has also been employed as an excipient in oral tablet and capsule formulations, where, depending on the grade, it serves as a controlled release agent to delay the release of a medicinal component into the digestive system. Hypromellose has also been utilized in ocular solutions. Additionally, it is a component of tablet coatings and is used as a binder.
