SODIUM PHENYLBUTYRATE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

SODIUM PHENYLBUTYRATE (UNII: NT6K61736T) (PHENYLBUTYRIC ACID - UNII:7WY7YBI87E)

Available from:

Mikart, Inc.

INN (International Name):

SODIUM PHENYLBUTYRATE

Composition:

SODIUM PHENYLBUTYRATE 500 mg

Prescription type:

PRESCRIPTION DRUG

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

SODIUM PHENYLBUTYRATE- SODIUM PHENYLBUTYRATE TABLET
MIKART, INC.
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DESCRIPTION
Sodium Phenylbutyrate Tablets for oral administration contain sodium
phenylbutyrate. Sodium
phenylbutyrate is an off-white crystalline substance which is soluble
in water and has a strong salty
taste. Sodium phenylbutyrate also is freely soluble in methanol and
practically insoluble in acetone and
diethyl ether. It is known chemically as 4-phenylbutyric acid, sodium
salt with a molecular weight of
186 and the molecular formula C
H O Na.
Chemical Structure:
Each tablet contains 500 mg of sodium phenylbutyrate and the inactive
ingredients silicon dioxide,
magnesium stearate and microcrystalline cellulose.
CLINICAL PHARMACOLOGY
Sodium phenylbutyrate is a pro-drug and is rapidly metabolized to
phenylacetate. Phenylacetate is a
metabolically-active compound that conjugates with glutamine via
acetylation to form
phenylacetylglutamine. Phenylacetylglutamine then is excreted by the
kidneys. On a molar basis, it is
comparable to urea (each containing two moles of nitrogen). Therefore,
phenylacetylglutamine
provides an alternate vehicle for waste nitrogen excretion.
PHARMACOKINETICS
GENERAL
Pharmacokinetic studies have not been conducted in the primary patient
population (neonates, infants, and
children), but pharmacokinetic data were obtained from normal adult
subjects.
ABS ORPTION
Peak plasma levels of phenylbutyrate occur within 1 hour after a
single dose of 5 grams of sodium
phenylbutyrate tablet with a C
of 218 μg/mL under fasting conditions. The effect of food on
phenylbutyrate’s absorption is unknown.
DIS POS ITION
The overall disposition of sodium phenylbutyrate and its metabolites
has not been characterized fully.
However, the drug is known to be metabolized to phenylacetate and
subsequently to
phenylacetylglutamine. Following oral administration of 5 grams
(tablets), measurable plasma levels of
phenylbutyrate and phenylacetate were detected 15 and 30 minutes after
dosing, respectively, and
phenylacetylglutamine was detected