Absorption, Distribution and Excretion
Does not penetrate the skin to a large degree, but enhances the ability of other chemicals to penetrate.
This drug's main metabolite is excreted in urine conjugated with glucuronic acid. No p-hydroxybenzohydrol was detected in urine or feces, in a study of pharmacokinetics in rats.
Solvents used in sunscreen products affect the stability and binding of the drug to the skin; in general, alcoholic solvents allow for the most rapid and deepest epidermal penetration of sunscreens. It appears that sunscreen agents are absorbed by the intact epidermis to varying degrees. /Sunscreens/

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Metabolism / Metabolites
Benzophenone's main metabolic pathway in the rabbit is by reduction to benzhydrol. A small amount (1%) is converted to p-hydroxybenzophenone following oral administration to rats.

Interactions
Agricultural workers are encouraged to use sunscreen to decrease the risk of UV-related skin cancer. Our previous studies have shown certain commercial sunscreens to be penetration enhancers. The focus of this project is to determine whether active ingredients in sunscreen formulations (i.e., the UV absorbing components and insect repellants for the sunscreen/bug repellant combinations) also act as dermal penetration enhancers for herbicides in vitro. The total percentages of 2,4-dichlorophenoxyacetic acid (2,4-D) penetrating through hairless mouse skin in 24 h ranged from 54.9 +/- 4.7 for the no sunscreen control to 86.9 +/- 2.5 for padimate-o. Of the active ingredients tested (7.5% octyl methoxycinnamate, 7% octocrylene, 0.6% oxybenzone, 5% homosalate, 5% octyl salicylate, 8% padimate-o, 10% sulisobenzone, and 9.5% and 19% N,N-diethyl-m-toluamide [DEET]), all but octocrylene led to a significant increase in total 2,4-D penetration as compared to the control (P < 0.05), and only octocrylene and oxybenzone did not significantly decrease the corresponding lag time. Octyl salicylate (P < 0.01) and octyl methoxycinnimate (P < 0.05) significantly increased the 3H2O penetration across mouse skin, indicating physical damage to the stratum corneum. Additional studies demonstrated that the penetration enhancement seen across hairless mouse skin also occurred with human skin. Thus, the active ingredients of sunscreen formulations enhance dermal penetration of the moderately lipophilic herbicide 2,4-D.
Diminish the penetration of ultraviolet (UV) light through the epidermis by absorbing UV radiation within a specific wavelength range. The amount and wavelength of UV radiation absorbed are affected by the molecular structure of the sunscreen agent. /Sunscreen agents, topical/

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Non-Human Toxicity Values
LD50 Rat oral 3530 mg/kg

Sulisobenzone is a member of benzophenones.
Sulisobenzone is approved by the FDA in concentrations of up to 10% and in Canada, is approved by Health Canada at the same concentrations. It works to filter out both UVA and UVB rays, protecting the skin from sun UV damage. The UV-filter substance, sulisobenzone (BP-4) is widely used an ingredient in sunscreens and other personal care products,. It falls under the drug category of benzophenones. The benzophenones are a group of aromatic ketones that have both pharmaceutical and industrial applications. Benzophenones may be found organically in fruits such as grapes. Benzophenones are used as photoinitiators, fragrance enhancers, ultraviolet curing agents, and, occasionally, as flavor ingredients; they are also used in the manufacture of insecticides, agricultural chemicals, and pharmaceuticals and as an additive for plastics, coatings, and adhesives. As a group, benzophenones may be used to delay photodegradation or extend shelf life in toiletries and plastic surface coatings.
See also: Octinoxate; sulisobenzone (component of); Ensulizole; sulisobenzone (component of) ... View More ...

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Drug Indication
Sunscreening agents are used to prevent sunburn, actinic keratosis, and premature skin aging and to reduce the incidence of skin cancer.

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Mechanism of Action
A surface coating of benzophenones decreases the amount of UV radiation absorbed by the skin by limiting the total amount of energy that reaches the skin. Benzophenone sunscreens, applied topically, protect the skin from these harmful effects of ultraviolet light by chemically absorbing light energy (photons). As this occurs, the benzophenone molecule becomes activated to higher energy levels. As the excited molecule returns to its ground state, the energy is released in the form of thermal energy. The hydroxyl group in the ortho position to the carbonyl group is believed to be a structural requirement for the benzophenones' absorption of UV light. This structural arrangement also contributes to the electronic stability of the molecule. Benzophenones absorb energy throughout the UV range, although the maximum UV absorbance is between 284 and 287 nm for the 2-hydroxybenzophenones.
Benzophenone sunscreens, applied topically, protect the skin from these harmful effects of ultraviolet light by chemically absorbing light energy (photons). As this occurs, the Benzophenone molecule becomes excited to higher energy levels. As the excited molecule returns to its ground state, the energy is released in the form of thermal energy. The hydroxyl group in the ortho position to the carbonyl group is believed to be a structural requirement for the Benzophenones' absorption of UV light. This structural arrangement also contributes to the electronic stability of the molecule. Thus, a surface coating of Benzophenones decreases the amount of UV radiation absorbed by the skin by limiting the total amount of energy that reaches the skin. Benzophenones absorb energy throughout the UV range, though maximum absorbance is between 284 and 287 nm for the 2-hydroxybenzophenones ...
Diminish the penetration of ultraviolet (UV) light through the epidermis by absorbing UV radiation within a specific wavelength range. The amount and wavelength of UV radiation absorbed are affected by the molecular structure of the sunscreen agent. /Sunscreen agents, topical/

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Therapeutic Uses
Daily use of a sunscreen with a high SPF (greater than 15) on usually exposed skin is recommended for residents of areas of high ... /solar radiation/ who work outdoors or ... /enjoy/ regular outdoor recreation. Daily use of a sunscreen can reduce the cumulative ... /solar/ exposure that causes actinic keratoses and squamous-cell carcinoma.
Sunscreen agents are indicated for the prevention of sunburn. In addition to limiting the skin's exposure to the sun, using sunscreen agents regularly when in the sun may help reduce long-term sun damage such as premature aging of the skin and skin cancer. /Sunscreen agents, topical; Included in US product labeling/

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Drug Warnings
The manufacturers of sunscreen preparations with propellants warn that concentrating and subsequently inhaling the fumes from these preparations may be harmful or fatal. /Propellants/
Because the absorptive characteristics of skin of children younger than 6 months of age may differ from those of adults and because the immaturity of metabolic and excretory pathways of these children may limit their ability to eliminate any percutaneously absorbed sunscreen agent, sunscreen products should be used in children younger than 6 months of age only as directed by a clinician. It is possible that the characteristics of geriatric skin also differ from those of skin in younger adults, but these characteristics and the need for special considerations regarding use of sunscreen preparations in this age group are poorly understood. /Sunscreens/
Little information is available regarding the safety of chronic sunscreen usage, but commercially available physical and chemical sunscreens appear to have a low incidence of adverse effects. Derivatives of PABA, benzophenone, cinnamic acid, and salicylate and 2-phenylbenzimidazole-5-sulfonic acid have caused skin irritation including burning, stinging, pruritus, and erythema on rare occasions. /Sunscreens/
Sunscreens should not be used as a means of extending the duration of solar exposure, such as prolonging sunbathing, and should not be used as a substitute for clothing on usually unexposed sites, such as the trunk and buttocks. /Sunscreens/
For more Drug Warnings (Complete) data for SULISOBENZONE (11 total), please visit the HSDB record page.

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Pharmacodynamics
Benzophenone sunscreens, applied topically, protect the skin from these harmful effects of ultraviolet light by chemically absorbing light energy (photons). Correct use of sunscreens serves to reduce the risk of sunburn. Sunscreen agents prevent the occurrence of squamous-cell carcinoma of the skin when used mainly during unintentional sun exposure. No conclusion can be drawn about the cancer-preventive activity of topical use of sunscreens against both basal-cell carcinoma and cutaneous melanoma. Use of sunscreens can extend the duration of intentional sun exposure, such as bathing in the sun.

C14H12O6S

308.3065

308.035

4065-45-6

6628-37-1 (mono-hydrochloride salt)

19988

White to off-white solid powder

1.4±0.1 g/cm3

0°C

170 °C

0°C

1.617

0.89

2

6

4

21

462

0

CXVGEDCSTKKODG-UHFFFAOYSA-N

InChI=1S/C14H12O6S/c1-20-12-8-11(15)10(7-13(12)21(17,18)19)14(16)9-5-3-2-4-6-9/h2-8,15H,1H3,(H,17,18,19)

5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ≥ 100 mg/mL (~324.35 mM)
DMSO : ≥ 34 mg/mL (~110.28 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)