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Tamiflu is an antiviral medication used to prevent the flu in exposed individuals. It is also used to shorten the duration of the flu virus in patients who have had flu symptoms for less than two days. It is available with a doctor’s prescription as an oral suspension or in capsules. There is only one active and several inactive ingredients in Tamiflu.

Active Ingredient

The suspension and capsules both contain oseltamivir phosphate as the active ingredient. It is an antiviral that attacks the flu virus and keeps it from reproducing in the body. The oral suspension, when constituted with water, contains 12 mg/ml oseltamivir base. Capsules are available in 30, 45 and 75 mg strengths.

Inactive Capsule Ingredients

Inactive ingredients include pregelatinized starch which acts as a binder in the capsules; talc which is used to dilute the ingredients in the capsules--it is essentially filler and is not absorbed by the body when ingested orally; providone K30, a pharmaceutical excipient that is used as a flow assistant in capsules; croscarmellose sodium, which acts like a sponge and absorbs water, helping the drug to disintegrate and disperse more readily; sodium stearyl fumarate, a capsule lubricant; and gelatin, a capsule coating and gelling agent.

Coloring Ingredients

All capsules contain FD&C Blue No. 2, a colorant used to print writing on each capsule. Titanium dioxide is also found in each capsule, and is used as a white pigment. In addition, the 30 mg capsule contains yellow iron oxide and red iron oxide; the 45 mg capsule contains black iron oxide; and the 75 mg capsule contains yellow, black and red iron oxide.

Inactive Oral Suspension Ingredients

Oral suspension inactive ingredients include sorbitol, a sugar-free sweetener; monosodium citrate, a buffering agent; xanthan gum, a stabilizer and thickener; titanium dioxide, a white pigment; tutti-frutti flavoring, artificial fruit flavoring used to improve the taste of the solution; sodium benzoate, a preservative; and saccharin sodium, an artificial sweetener.