A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Thyrogen Online, Description, Chemistry, Ingredients - Thyrotropin Alfa
Thyrogen Online, Description, Chemistry, Ingredients - Thyrotropin Alfa
DESCRIPTION
Thyrogen® (thyrotropin alfa for injection) contains a highly purified recombinant
form of human thyroid stimulating hormone (TSH), a glycoprotein which is produced
by recombinant DNA technology. Thyrotropin alfa is synthesized in a genetically
modified Chinese hamster ovary cell line.
Thyrotropin alfa is a heterodimeric glycoprotein comprised of two non-covalently
linked subunits, an alpha subunit of 92 amino acid residues containing two N-linked
glycosylation sites and a beta subunit of 118 residues containing one N-linked
glycosylation site. The amino acid sequence of thyrotropin alfa is identical
to that of human pituitary thyroid stimulating hormone.
Both thyrotropin alfa and naturally occurring human pituitary thyroid stimulating
hormone are synthesized as a mixture of glycosylation variants. Unlike pituitary
TSH, which is secreted as a mixture of sialylated and sulfated forms, thyrotropin
alfa is sialylated but not sulfated. The biological activity of thyrotropin
alfa is determined using both an in vivo bioassay and an in vitro
bioassay. The in vivo bioassay measures an increase in thyroxine
(T 4 ) level in response to the intraperitoneal injection of thyrotropin
alfa after suppression of endogenous TSH levels in mice. The in vitro assay
measures the amount of cAMP produced by a bovine thyroid-derived microsome preparation
in response to thyrotropin alfa. The specific activity of thyrotropin alfa is
calibrated against the World Health Organization (WHO) human pituitary derived
TSH reference standard, NIBSC 84/703. The biological activity of thyrotropin
alfa has been determined to be no less than 4 IU/mg by the in vitro bioassay.
Thyrogen is supplied as a sterile, non-pyrogenic, white to off-white lyophilized
product, intended for intramuscular (IM) administration after reconstitution
with Sterile Water for Injection, USP. Each vial of Thyrogen contains 1.1 mg
thyrotropin alfa ( ≥ 4 IU), 36 mg Mannitol, 5.1 mg Sodium Phosphate, and
2.4 mg Sodium Chloride.
After reconstitution with 1.2 mL of Sterile Water for Injection, USP, the thyrotropin
alfa concentration is 0.9 mg/mL. The pH of the reconstituted solution is approximately
7.0.
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