Description, Chemicals and Ingredients
The active ingredient in Allegra is Fexofenadine hydrochloride is a counteracting
substance to histamine (produced from the amino
acid histidine causing dilution of blood vessels)
and it is chemically known as dimethyl benzeneacetic
acid hydrochloride.
As far as chemical structure is concerned, the
molecular weight (which is the weight gotten by
totaling the weight of its constituent items)
of this substance is 538.13. Its empirical formula
is C32H39NO4.
Fexofenadine hydrochloride appears to be a white
or off-whitish crystalline powder. Due to its
powdery nature, it dissolves easily and completely
in ethanol and methanol (which is a poisonous,
volatile and inflammable alcohol). It does not
dissolve as much in chloroform and water and does
not dissolve at all in hexane. A zwitterion is
defined as a dipolar ion which contains an equal
strength of positive and negative ions, i.e. cations
and anions. Fexofenadine hydrochloride acts as
a zwitterion when placed in water or other aqueous
media at a neutral Ph value.
The formulation of Allegra can be
either in tablet or capsule form, for oral administration.
Basically, each capsule contains 60 mg of fexofenadine
hydrochloride, the principal constituent and the
following other substances which are largely inert:
croscarmellose sodium, gelatin, lactose, microcrystalline
cellulose, and pregelatinized starch. The dosage
strength however can vary, and a capsule may contain
30mg, 60 mg or even 180mg of fexofenadine hydrochloride,
as per requirement of the patient.
The coating of the capsule is slightly watery
and is prepared from a medicinal powder made from
hydroxypropyl methylcellu-lose, iron-oxide blends,
polyethylene glycol, povidone, silicon dioxide
and titanium dioxide. |
