Monobenzone

Monobenzone

Systematic (IUPAC) name
4-(benzyloxy)phenol
Clinical data
AHFS/Drugs.com	International Drug Names
Pregnancy cat.	?
Legal status	? (CA) ? (US)
Routes	Topical
Identifiers
CAS number	103-16-2 Y
ATC code	D11AX13
PubChem	CID 7638
DrugBank	DB00600
ChemSpider	7356 N
UNII	9L2KA76MG5 N
KEGG	D05072 Y
ChEMBL	CHEMBL1388 N
Synonyms	Hydroquinone benzyl ether, Hydroquinone monobenzyl ether, Benzyl p-hydroxyphenyl ether, Benzyl hydroquinone, Benzoquin, 4-(phenylmethoxy)phenol
Chemical data
Formula	C13H12O2
Mol. mass	200.233180 g/mol
N(what is this?)  (verify)

Monobenzone is a compound used as a topical drug for medical depigmentation.

Chemistry

Monobenzone is the monobenzyl ether of hydroquinone. Monobenzone occurs as a white, almost tasteless crystalline powder, soluble in alcohol and practically insoluble in water.

Pharmacology

The topical application of monobenzone in animals decreases the excretion of melanin from melanocytes. The same action is thought to be responsible for the depigmenting effect of the drug in humans. Monobenzone may cause destruction of melanocytes and permanent depigmentation.

The histology of the skin after depigmentation with topical monobenzone is the same as that seen in vitiligo; the epidermis is normal except for the absence of identifiable melanocytes. Therefore, monobenzone is used as a topical medicine to permanently depigment normal skin surrounding vitiliginous lesions only in patients with disseminated (greater than 50 percent of body surface area) idiopathic vitiligo.

Vitiligo

Vitiligo is a chronic skin disease that causes loss of melanocytes which are pigment-producing cells, resulting in irregular pale or white patches of skin. The cellular and molecular mechanisms leading to the destruction of melanocytes in this disorder have not yet been detected. Vitiligo affects approximately 0.5 to 1 percent of the population. Individuals of all ethnic origins and both sexes can be affected; however, it is much more noticeable on darker skin. Common areas of the skin losing pigment are the face, lips, hands, arms, legs, and genital areas. Patches of the epidermis affected by vitiligo often occur symmetrically across both sides on the body. Seldom, small areas of the body may repigment as they are recolonised by melanocytes.

There is no known cure for the disease but treatments do exist. Some patients use cosmetic make-up to cover the white spots, while others use treatments such as repigmentation through a series of ultraviolet light treatments and surgical transplant of melanocytes. In severe cases, when over fifty percent of the body surface area is covered with white patches, patients cannot use these repigmentation treatments. They can, however, choose to eliminate the skin colour from the normal areas using monobenzone cream, a process called depigmentation. This gives the patient’s skin a permanent, even, pale white colour. Since the application of monobenzone is topical, it can be done in the privacy of one’s home. It is simple to do and does not require frequent visits to a doctor’s office. Twice daily monobenzone topical cream must be applied.

The major side effect of depigmentation therapy is inflammation (redness and swelling) of the skin. Patients may experience itching or dry skin. The process of depigmentation is gradual. The length of time using monobenzone topical cream ranges from four months to a year. The patient must understand the concept of continued existence of a source of follicular melanocytes and that exposure to the sun can lead to perifollicular pigmented macules. Rigorous limitation of sun exposure is essential following depigmentation therapy, not only to avoid burns, but to avoid perifollicular repigmentation. Wearing high-SPF sunscreens is the ultimate physical barrier to help avoid burns and repigmentation.

There are at least three theories about the principal cause of vitiligo:

• Nerve endings in the skin release a chemical that is toxic to the melanocytes.
• Melanocytes simply self-destruct.
• It is a type of autoimmune disease in which the immune system targets the body's own cells and tissues.

References

• "Skin bleaching with monobenzone." Skin Whitening and Skin Lightening Resources. Skin Whitening and Skin Lightening Resources, 20 Apr. 2010. Web. 20 Apr. 2010. <http://www.whiterskin.info/skin-bleaching-with-monobenzone/comment-page-1/>.
• /Bolognia, Jean, Kim Lapia, and Sandra Somma. "Depigmentation therapy." EBSCOhost. Blackwell Science 2001, n.d. Web. 20 Apr. 2010. <http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=4&hid=108&sid=166272c4-1bc8-40c5-8288-c62ad83b0327%40sessionmgr11