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
Emla Online, Description, Chemistry, Ingredients - Lidocaine and Prilocaine
Emla Online, Description, Chemistry, Ingredients - Lidocaine and Prilocaine
DESCRIPTION
EMLA Cream (lidocaine 2.5% and prilocaine 2.5%) is an emulsion
in which the oil phase
is a eutectic mixture
of lidocaine and prilocaine
in a ratio of 1:1 by weight. This eutectic
mixture has a melting point
below room temperature and therefore both local
anesthetics exist as a liquid
oil rather than as crystals. It is packaged in 5 gram
and 30 gram tubes. It is also
packaged in the Anesthetic Disc, which is a single-dose unit
of EMLA contained within an occlusive
dressing. The Anesthetic Disc is composed of a laminate backing, an absorbent
cellulose disc, and an adhesive
tape ring. The disc contains
1 gram of EMLA
emulsion, the active contact
surface being approximately 10 cm2. The surface
area of the entire
anesthetic disc is approximately
40 cm2.
Lidocaine is chemically designated as acetamide, 2-(diethylamino)-N-
(2,6-dimethylphenyl), has an octanol:water partition ratio
of 43 at pH 7.4, and has the following molecular formula C14H22N2O
with a molecular weight of 234.3.
Prilocaine is chemically designated as propanamide, N-(2-methylphenyl)-2-
(propylamino), has an octanol:water partition ratio
of 25 at pH 7.4, and has the following
molecular formula C13H20N2O with a molecular weight of 220.3.
Each gram of EMLA
contains lidocaine 25 mg,
prilocaine 25 mg, polyoxyethylene fatty acid
esters (as emulsifiers), carboxypolymethylene (as a thickening agent),
sodium hydroxide
to adjust to a pH approximating
9, and purified water to 1 gram. EMLA
contains no preservative, however it passes the USP antimicrobial effectiveness
test due to the pH. The specific
gravity of EMLA Cream is 1.00.
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