Clinical data | |
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Trade names | Benzac, Panoxyl, others |
Other names | benzoperoxide, dibenzoyl peroxide (DBPO), BPO |
AHFS/Drugs.com | Professional Drug Facts |
MedlinePlus | a601026 |
License data | |
Routes of administration | Topical |
ATC code | |
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Identifiers | |
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CAS Number | |
PubChem CID | |
DrugBank | |
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CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.002.116 |
Chemical and physical data | |
Formula | C14H10O4 |
Molar mass | 242.230 g·mol−1 |
3D model (JSmol) | |
Density | 1.334 g/cm3 |
Melting point | 103 to 105 °C (217 to 221 °F) decomposes |
Solubility in water | poor mg/mL (20 °C) |
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Data page | |
Benzoyl peroxide (data page) |
Benzoyl peroxide is a chemical compound (specifically, an organic peroxide) with structural formula (C6H5−C(=O)O−)2, often abbreviated as (BzO)2. In terms of its structure, the molecule can be described as two benzoyl (C6H5−C(=O)−, Bz) groups connected by a peroxide (−O−O−). It is a white granular solid with a faint odour of benzaldehyde, poorly soluble in water but soluble in acetone, ethanol, and many other organic solvents. Benzoyl peroxide is an oxidizer, which is principally used in the production of polymers. [5]
Benzoyl peroxide is mainly used in production of plastics [5] [6] and for bleaching flour, hair, plastics and textiles. [7] [8]
As a bleach, it has been used as a medication and a water disinfectant. [6] [8]
As a medication, benzoyl peroxide is mostly used to treat acne, either alone or in combination with other treatments. [9] Some versions are sold mixed with antibiotics such as clindamycin. [10] [11] It is on the World Health Organization's List of Essential Medicines. [12] It is available as an over-the-counter and generic medication. [13] [10] It is also used in dentistry for teeth whitening. In 2021, it was the 284th most commonly prescribed medication in the United States, with more than 700,000 prescriptions. [14] [15]
Benzoyl peroxide was first prepared and described by Justus von Liebig in 1858. [16] Donald Holroyde Hey FRS [17] (12 September 1904 – 21 January 1987) was a Welsh organic chemist who inferred that the decomposition of benzoyl peroxide generated free phenyl radicals. [18] [19]
The original 1858 synthesis by Liebig reacted benzoyl chloride with barium peroxide, [16] a reaction that probably follows this equation:
Benzoyl peroxide is usually prepared by treating hydrogen peroxide with benzoyl chloride under alkaline conditions.
The oxygen–oxygen bond in peroxides is weak. Thus, benzoyl peroxide readily undergoes homolysis (symmetrical fission), forming free radicals:
The symbol • indicates that the products are radicals; i.e., they contain at least one unpaired electron. Such species are highly reactive. The homolysis is usually induced by heating. The half-life of benzoyl peroxide is one hour at 92 °C. At 131 °C, the half-life is one minute. [21]
In 1901, it was observed that the compound made the tincture of guaiacum tincture turn blue, a sign of oxygen being released. [22] Around 1905, Loevenhart reported on the successful use of benzoyl peroxide to treat various skin conditions, including burns, chronic varicose leg tumors, and tinea sycosis. He also reported animal experiments that showed the relatively low toxicity of the compound. [23] [7] [24]
Treatment with benzoyl peroxide was proposed for wounds in 1929, and for sycosis vulgaris and acne varioliformis in 1934. [24] However, preparations were often of questionable quality. [7] It was officially approved for the treatment of acne in the US in 1960. [7]
Benzoyl peroxide is mainly used as a radical initiator to induce chain-growth polymerization reactions, [5] such as for polyester and poly(methyl methacrylate) (PMMA) resins and dental cements and restoratives. [25] It is the most important among the various organic peroxides used for this purpose, a relatively safe alternative to the much more hazardous methyl ethyl ketone peroxide. [26] [27] It is also used in rubber curing and as a finishing agent for some acetate yarns. [25]
Benzoyl peroxide is effective for treating acne lesions. It does not induce antibiotic resistance. [28] [29] It may be combined with salicylic acid, sulfur, erythromycin or clindamycin (antibiotics), or adapalene (a synthetic retinoid). Two common combination drugs include benzoyl peroxide/clindamycin and adapalene/benzoyl peroxide, adapalene being a chemically stable retinoid that can be combined with benzoyl peroxide [30] unlike tezarotene and tretinoin. Combination products such as benzoyl peroxide/clindamycin and benzoyl peroxide/salicylic acid appear to be slightly more effective than benzoyl peroxide alone for the treatment of acne lesions. [29] The combination tretinoin/benzoyl peroxide was approved for medical use in the United States in 2021.
Benzoyl peroxide for acne treatment is typically applied to the affected areas in gel, cream, or liquid, in concentrations of 2.5% increasing through 5.0%, and up to 10%. [28] No strong evidence supports the idea that higher concentrations of benzoyl peroxide are more effective than lower concentrations. [28]
Classically, benzoyl peroxide is thought to have a three-fold activity in treating acne. It is sebostatic, comedolytic, and inhibits growth of Cutibacterium acnes , the main bacterium associated with acne. [28] [31] In general, acne vulgaris is a hormone-mediated inflammation of sebaceous glands and hair follicles. Hormone changes cause an increase in keratin and sebum production, leading to blocked drainage. C. acnes has many lytic enzymes that break down the proteins and lipids in the sebum, leading to an inflammatory response. The free-radical reaction of benzoyl peroxide can break down the keratin, therefore unblocking the drainage of sebum (comedolytic). It can cause nonspecific peroxidation of C. acnes, making it bactericidal, [7] and it was thought to decrease sebum production, but disagreement exists within the literature on this. [31] [32]
Some evidence suggests that benzoyl peroxide has an anti-inflammatory effect as well. In micromolar concentrations it prevents neutrophils from releasing reactive oxygen species, part of the inflammatory response in acne. [32]
Application of benzoyl peroxide to the skin may result in redness, burning, and irritation. This side effect is dose-dependent. [9] [13]
Because of these possible side effects, it is recommended to start with a low concentration and build up as appropriate, as the skin gradually develops tolerance to the medication. Skin sensitivity typically resolves after a few weeks of continuous use. [32] [33] Irritation can also be reduced by avoiding harsh facial cleansers and wearing sunscreen prior to sun exposure. [33]
One in 500 people experience hypersensitivity to benzoyl peroxide and are liable to experience burning, itching, crusting, and possibly swelling. [34] [35] About one-third of people experience phototoxicity under exposure to ultraviolet (UVB) light. [36]
In the US, the typical concentration for benzoyl peroxide is 2.5% to 10% for both prescription and over-the-counter drug preparations that are used in treatment for acne. [37]
Benzoyl peroxide is used in dentistry as a tooth whitening product. [38]
Benzoyl peroxide is potentially explosive [39] like other organic peroxides, and can cause fires without external ignition. The hazard is acute for the pure material, so the compound is generally used as a solution or a paste. For example, cosmetics contain only a small percentage of benzoyl peroxide and pose no explosion risk.
Benzoyl peroxide breaks down in contact with skin, producing benzoic acid and oxygen, neither of which is very toxic. [40]
The carcinogenic potential of benzoyl peroxide has been investigated. A 1981 study published in the journal Science found that although benzoyl peroxide is not a carcinogen, it does promote cell growth when applied to an initiated tumor. The study concluded, "caution should be recommended in the use of this and other free radical-generating compounds". [41]
A 1999 IARC review of carcinogenicity studies found no convincing evidence linking benzoyl peroxide acne medication to skin cancers in humans. However, some animal studies found that the compound could act as a carcinogen and enhance the effect of known carcinogens. [25]
Benzoyl peroxide can break down into carcinogen benzene at temperatures above 50 °C. [42] [43]
In a 1977, study using a human maximization test, 76% of subjects acquired a contact sensitization to benzoyl peroxide. Formulations of 5% and 10% were used. [44]
The US National Institute for Occupational Safety and Health has developed criteria for a recommended standard for occupational exposure to benzoyl peroxide. [45]
Contact with fabrics or hair, such as from still-moist acne medication, can cause permanent color dampening almost immediately. Even secondary contact can cause bleaching, for example, contact with a towel that has been used to wash off benzoyl peroxide-containing hygiene products. [46]
Acne, also known as acne vulgaris, is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and possible scarring. It primarily affects skin with a relatively high number of oil glands, including the face, upper part of the chest, and back. The resulting appearance can lead to lack of confidence, anxiety, reduced self-esteem, and, in extreme cases, depression or thoughts of suicide.
Minocycline, sold under the brand name Minocin among others, is a tetracycline antibiotic medication used to treat a number of bacterial infections such as some occurring in certain forms of pneumonia. It is generally less preferred than the tetracycline doxycycline. Minocycline is also used for the treatment of acne and rheumatoid arthritis. It is taken by mouth or applied to the skin.
A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Surrounding the female nipples, areolar glands are specialized sebaceous glands for lubricating the nipples. Fordyce spots are benign, visible, sebaceous glands found usually on the lips, gums and inner cheeks, and genitals.
Cutibacterium acnes is the relatively slow-growing, typically aerotolerant anaerobic, gram-positive bacterium (rod) linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. Its genome has been sequenced and a study has shown several genes can generate enzymes for degrading skin and proteins that may be immunogenic.
Clindamycin is a lincosamide antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media, and endocarditis. It can also be used to treat acne, and some cases of methicillin-resistant Staphylococcus aureus (MRSA). In combination with quinine, it can be used to treat malaria. It is available by mouth, by injection into a vein, and as a cream or a gel to be applied to the skin or in the vagina.
Tretinoin, also known as all-trans retinoic acid (ATRA), is a medication used for the treatment of acne and acute promyelocytic leukemia. For acne, it is applied to the skin as a cream, gel or ointment. For acute promyelocytic leukemia, it is effective only when the RARA-PML fusion mutation is present and is taken by mouth for up to three months. Topical tretinoin is also the most extensively investigated retinoid therapy for photoaging.
Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, enlarged nose may occur in severe disease, a condition known as rhinophyma.
ATC code D10Anti-acne preparations is a therapeutic subgroup of the Anatomical Therapeutic Chemical Classification System, a system of alphanumeric codes developed by the World Health Organization (WHO) for the classification of drugs and other medical products. Subgroup D10 is part of the anatomical group D Dermatologicals.
Adapalene, sold under the brand name Differin among others, is a third-generation topical retinoid primarily used in the treatment of mild-moderate acne, and is also used off-label to treat keratosis pilaris as well as other skin conditions. Studies have found adapalene is as effective as other retinoids, while causing less irritation. It also has several advantages over other retinoids. The adapalene molecule is more stable compared to tretinoin and tazarotene, which leads to less concern for photodegradation. It is also chemically more stable compared to the other two retinoids, allowing it to be used in combination with benzoyl peroxide. Due to its effects on keratinocyte proliferation and differentiation, adapalene is superior to tretinoin for the treatment of comedonal acne and is often used as a first-line agent. The Swiss company Galderma developed adapalene.
Pseudofolliculitis barbae (PFB) is a type of irritant folliculitis that commonly affects people who have curly or coarse facial hair. It occurs when hair curls back into the skin after shaving, causing inflammation, redness, and bumps. This can lead to ingrown hairs, scarring, and skin discoloration. PFB can be treated with various methods, including changing shaving habits, using topical creams or ointments, and undergoing laser hair removal. Prevention measures include proper shaving techniques, using sharp razors, and avoiding too close a shave.
Tazarotene, sold under the brand name Tazorac, among others, is a third-generation prescription topical retinoid. It is primarily used for the treatment of plaque psoriasis and acne. Tazarotene is also used as a therapeutic for photoaged and photodamaged skin. It is a member of the acetylenic class of retinoids.
Proactiv is an American brand of skin-care products developed by two American dermatologists, Katie Rodan and Kathy A. Fields, and launched in 1995 by Guthy-Renker, a California-based direct marketing company, that was endorsed by famous celebrities The range includes moisturizers, body washes and treatment products, but the brand is known for its three-step anti-acne Solutions 3-step routine consisting of a BPO cleanser, glycolic toner and treatment lotion. Proactiv+, a reformulation of the three-step kit, was introduced in 2013, and in 2017, ProactivMD launches powered by Adapalene.
Clindamycin/benzoyl peroxide, sold under the brand name Benzaclin among others, is a topical gel used for the treatment of acne. It is a fixed-dose combination of clindamycin, as the phosphate, an antibiotic; and benzoyl peroxide, an antiseptic.
Pitted keratolysis is a bacterial skin infection of the foot. The infection is characterized by craterlike pits on the sole of the feet and toes, particularly weight-bearing areas.
Neonatal acne, also known as acne neonatorum, is a type of acne that develops in newborns, typically within the first six weeks of life. It presents with open and closed comedones on the cheeks, chin and forehead.
A pimple or zit is a kind of comedo that results from excess sebum and dead skin cells getting trapped in the pores of the skin. In its aggravated state, it may evolve into a pustule or papule. Pimples can be treated by acne medications, antibiotics, and anti-inflammatories prescribed by a physician, or various over the counter remedies purchased at a pharmacy.
Adapalene/benzoyl peroxide, sold under the brand name Epiduo among others, is a fixed-dose combination medication for the treatment of acne vulgaris. It is a combination of adapalene, a retinoid; and benzoyl peroxide.
Infantile acne is a form of acne that begins in very young children. Typical symptoms include inflammatory and noninflammatory lesions, papules and pustules most commonly present on the face. No cause of infantile acne has been established but it may be caused by increased sebaceous gland secretions due to elevated androgens, genetics and the fetal adrenal gland causing increased sebum production. Infantile acne can resolve by itself by age 1 or 2. However, treatment options include topical benzyl peroxide, topical retinoids and topical antibiotics in most cases.
Tretinoin/benzoyl peroxide, sold under the brand name Twyneo, is a fixed-dose combination medication used for the treatment of acne. It contains tretinoin, a vitamin A derivative, and benzoyl peroxide, an oxidizing agent.
Clindamycin/adapalene/benzoyl peroxide, sold under the brand name Cabtreo, is a fixed-dose combination medication used for the treatment of acne. It contains clindamycin, as the phosphate, a lincosamide antibacterial; adapalene, a synthetic retinoid; and benzoyl peroxide, an oxidizing agent. It is applied to the skin.