Ingredients in Viagra

Viagra is made up of several active and inactive ingredients that when combined have the ability to perform Viagra’s main function: to inhibit the enzyme phosphodiesterase 5 (PDE5). The PDE5 enzyme is responsible for controlling the blood vessels in certain parts of the body.

Most people will recognise Viagra as a medication for erectile dysfunction. However, Viagra is able to target the blood vessels in two main areas of the human body – the male penis and the lungs of both male and female individuals. The PDE5 enzyme, when too active, can cause the blood vessels to tense up or constrict blood flow.

When a man suffers from erectile dysfunction, it is because this enzyme is overactive and does not allow proper blood flow to the penis. Viagra is also used to relax the blood vessels in the lungs. People who suffer from pulmonary arterial hypertension are prescribed Viagra to help ease the symptoms of respiratory hypertension.

Active Ingredient in Viagra

 

Viagra has one active ingredient, a citrate salt known as Sildenafil. This salt, when dissolved in the body, causes nitrous oxide to be released in the blood. When nitrous oxide is released, it causes the blood vessels to relax and enlarge, thus allowing for increased blood flow. This salt is a known inhibitor of PDE5.

The chemical structure of the active ingredient in Viagra is displayed:

This citrate-based salt is water soluble and thus the ingredient of choice for this product.

Inactive Ingredients in Viagra

 

Viagra is made up of several inactive ingredients, also known as excipients. These ingredients have no effect whatsoever on the key operation of the drug. They are included into the overall formula of the drug Viagra in order to minimise possible side effects, ease the use of the drug, and provide indirect support of the key active ingredient.

It is important to know these ingredients before you take Viagra. When talking to your doctor about being prescribed this drug, make sure you alert them to any allergies you may have to these ingredients.

The key inactive ingredients for Viagra are:

  • Microcrystalline Cellulose – This is a glucose-based polymer that acts as an emulsifier for the key ingredient in Viagra, Sildenafil. It allows the salt to be properly dissolved and distributed into the blood stream. Emulsifiers help to stabilise and mix chemicals that would not normally mix, such as oil and water.
  • Sodium Croscarmellose – This ingredient increases the amount of water in which the salt can be dissolved. In essence, it allows the distribution of dissolved Sildenafil to be increased and results in greater bioavailability of the drug.
  • Hypromellose – The function of this inactive ingredient is to control the release of the pill form of Viagra. It acts as a time release for the drug into the body. If the pill dissolves before it reaches the stomach, for example, the body will not properly absorb the drug. Hypromellose is the primary reason it takes approximately 30 minutes to start feeling the effects of Viagra set in.
  • Anhydrous Dibasic Calcium Phosphate – This ingredient adds bulk to the pill. The actual measurable amount of Sildenafil needed in each pill is nearly microscopic and by itself could not be handled let alone seen. This ingredient gives Viagra an easy to swallow size while allowing it to be properly handled by the patient’s hands.
  • Magnesium Stearate – This ingredient is yet another time release agent. It is slightly hydrophobic, meaning that it works to repel water, but only for a time. Eventually, it will succumb to wettability and allow the release of Viagra into the body.
  • Titanium Dioxide – In addition to being a colouring agent, Titanium dioxide aids in hydrolysis. Hydrolysis allows for certain chemicals to be bonded to water. Since Viagra needs to be chemically bonded to the water in the body for both dissolution and transport, this ingredient is crucial to that process.
  • Triacetin – This one can be added to the list of solvents. It simply adds to the pill’s ability to dissolve properly.
  • Lactose – A form of sugar, lactose helps carry the active ingredient in Viagra to the proper places in the body. Since the body accepts lactose very well, it also prevents the body from rejecting the ingredients and rendering the drug inert.