According to Chemie.de, Viagra is a brand-name drug developed and marketed by Pfizer that was approved in 1998 by the FDA to treat erectile dysfunction, although initially it was studied for high blood pressure and angina pains. The active ingredient in Viagra is sildenafil citrate, a selective inhibitor of an enzyme which allows for smooth muscle relaxation and increased blood flow in the penis, according to RxList.com. Drugs.com notes that Viagra is formulated as blue, diamond-shaped tablets equivalent to 25, 50 and 100 mg for oral administration. In addition to the active ingredient of sildenafil, Viagra also contains many inactive ingredients.
Sildenafil Citrate
According to DrugLib.com, sildenafil enhances the effect of nitric oxide by inhibiting the enzyme phosphodiesterase type 5, which causes increased levels of cyclic guanosine monophosphate in the brain’s corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the penis. It is claimed that sildenafil, at recommended doses, has no effect in the absence of sexual stimulation.
Inactive Binding & Filling Agents
According to Daily Med, Viagra contains four inactive ingredients that can generally be called binders or fillers: microcrystalline cellulose, hypromellose, lactose and anhydrous calcium phosphate. Binders keep all the ingredients intact and ensure that pills can be created under the pressures of the compounding process. Binders are usually starches, sugars or cellulose. The cellulose, lactose and phosphate compounds also act as fillers, which make the tablet larger, making it practical for manufacturing and convenient for the consumer to handle, according to Chemie.de. As a rule, fillers should be chemically inert, compatible with other ingredients, water soluble, colorless and tasteless.
Inactive Disintegrating Agent
Viagra also contains croscarmellose sodium, which acts primarily as a filler in pharmaceutical pills, but it also helps the pill’s ingredients quickly disintegrate and become absorbed by the lower gut, according to Chemie.de. Specifically, it’s a cross-linked methyl cellulose compound that absorbs water and aids in the absorption of Viagra’s active ingredient, sildenafil citrate.
Inactive Lubricating & Mixing Agents
Magnesium stearate is another ingredient in Viagra, and it acts as both a lubricant and stabilizer in the compounding process of tablet manufacturing. Magnesium stearate combines with another ingredient, triacetin, to help mix the ingredients evenly, according to Chemie.de. Triacetin is a very basic fatty acid that is a common food additive and also used as a solvent. Lubricants assist with the flow of powdered ingredients through production and help prevent them from sticking to the manufacturing equipment.
Inactive Coloring Agents
All Viagra pills, regardless of dosage, contain FD & C blue #2 edible ink, giving them the characteristic medium blue appearance, according to Daily Med. Titanium dioxide is another ingredient used for coloring because of its ability to provide brightness and opacity to many products in pill form.
