Vexa-D

Generic name: lidocaine, allantoin, petrolatum
Dosage form: patch

Medically reviewed by Drugs.com. Last updated on Feb 21, 2022.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Active Ingredients

Allantoin

Lidocaine

Petrolatum

DESCRIPTION:
Vexa-D (Allantoin 2%/Lidocaine 4%/Petrolatum 30%) is comprised of an adhesive material containing Allantoin 2%, Lidocaine 4% and petrolatum 30% which is applied to a woven polyester backing and covered with a PET film release line. The release liner is removed prior to application to the skin. The size of the patch is 12.5 cm x 8.5cm.
Allantoin is chemically designated as 1-(2,5-Dioxo-4-imidazolidinyl). It is a white powder that is stable, incompatible with strong oxidizing agents. It has a melting point of 230°C. It has the following structure:
Lidocaine is chemically designated as 2-(diethylamino)-N-(2,6-dimethylphenyl), has an octanol: water partition ration of 43 at pH 7.4, and has the following structure:
Each adhesive patch contains 34 mg of Allantoin and 68 mg of Lidocaine in a petrolatum base. It also contains the following inactive ingredients: Vitamin E and Onion Extract.
CLINICAL PHARMACOLOGY:
Pharmacodynamics
Allantoin works by slowing bacterial growth and loosing and softening scales and crust. The keratolytic effect and abrasive and astringent properties of Allantoin are used in skin softening cosmetic preparation.
Allantoin is a moisturizing, soothing, healing, anti-irritating, keratoyltic and non-toxic agent. Allantoin is a cell-proliferation healing agent which stimulates healthy tissue formation. It removes necrotic and scaling tissue.
Lidocaine is an amide-type local anesthetic agent and is suggested to stabilize neuronal membranes by inhibiting the ionic fluxes required for the initiation and conduction of impulses.
The penetration of Lidocaine into intact skin after application of patch is sufficient to produce an analgesic effect, but less than the amount necessary to produce a complete sensory block.
Pharmacokinetics
Absorption
The amount of allantoin and lidocaine systemically absorbed is directly related to both the duration of application and the surface area over which it is applied.
In a pharmacokinetic study, three lidocaine 5% patches were applied over an area of 420 cm2 of intact skin on the back of normal volunteers for 12 hours. Blood samples were withdrawn for a determination of lidocaine concentration during the application and for 12 hours after removal of patches. The results are summarized in table 1.
Table 1
Absorption of Lidocaine
Normal volunteers (n=15, 12-hour wearing time)
Application Site
Area
(cm2 )
Dose Absorbed (mg)
Cmax
(μg/mL)
Tmax
(hr)
3 Patches (2100 mg)
Back
420
64 ± 32
0.13 ± 0.06
11 hr
When lidocaine 5% patch is used acco