Tar preparation

Steinkohlenteer, m. coal tar. -benzin, n. benzene benzol(e), -blase,/. coal-tar still, -essenz, /. first light oil. -farbe, /. coal-tar color, -kampher, m. naphthalene, -dl, n. coal-tar oil (leichtes, light oil schweres, heavy oil), -pech, n. coal-tar pitch, -prl-parat, n. coal-tar preparation, coal-tar prod uct-... 

Topical therapy is the initial drug treatment strategy for patients with mild to moderate psoriasis. It is estimated that approximately 70% to 80% of all patients with psoriasis can he treated adequately with use of topical therapy.1 Topical therapies include corticosteroids, coal tar products, anthralin, vitamin D3 analogues such as calcipotriol, retinoids such as tazarotene, and topical immunomodulators such as tacrolimus and pime-crolimus.18 Vitamin D3 analogues and topical retinoids all affect keratinocyte functions and the immune response. Currently, these are in wider use than is either anthralin or coal tar preparations. 

Coal tar preparations of 2% to 5% tar are available in lotions, creams, shampoos, ointments, gels, and solutions. It is usually applied directly to lesions in the evening and allowed to remain in skin contact through the night. It may also be used in bathwater. 

The chemical composition of birch bark tar is dependent on the temperature at which tar is produced. In producing simulated tars in the laboratory for comparison with an adhesive used to repair a Roman jar from Stan wick, Charters et al. (1993) found that tars prepared at 350 °C displayed an increase in triterpenoid hydrocarbons as well as unresolved components presumably resulting from pyrolysis, although the precise nature of these molecules has not been elucidated. Binder et al. (1990) and Charters et al. (1993) also report the presence of allobetul-2-ene [Structure 7.24] in aged birch bark tars. Since this molecule has not been reported in extracts from fresh birch bark, it could be formed during heating to produce the tar (Regert et al., 2003). 

Certain industrial populations exposed to coal tar products have a demonstrated risk of skin cancer. Substances containing polycyclic hydrocarbons or polynuclear aromatics (PNAs), which may produce skin cancer, also produce contact dermatitis (e.g., coal tar pitch, cutting oils)." Although allergic dermatitis is readily induced by PNAs in guinea pigs, it only rarely is reported in humans from occupational contact with PNAs. Incidences in humans have resulted largely from the therapeutic use of coal tar preparations. ... 

Xwwrmxw.—ln Baugoon petroleum sud in ooal tar. Preparation.—1. By heating benzoic acid with excess of lime or baryta —... 

Tar preparations are used mainly in the treatment of psoriasis, dermatitis, and lichen simplex chronicus. The phenolic constituents endow these compounds with antipruritic properties, making them particularly valuable in the treatment of chronic lichenified dermatitis. Acute dermatitis with vesiculation and oozing may be irritated by even weak tar preparations, which should be avoided. However, in the subacute and chronic stages of dermatitis and psoriasis, these preparations are quite useful and offer an alternative to the use of topical corticosteroids. 

The most common adverse reaction to coal tar compounds is an irritant folliculitis, necessitating discontinuance of therapy to the affected areas for a period of 3-5 days. Phototoxicity and allergic contact dermatitis may also occur. Tar preparations should be avoided in patients who have previously exhibited sensitivity to them. 

Brockow, K. et al., Effect of gentian violet, corticosteroid and tar preparations in Staphylococcus-aureus-colonized atopic eczema. Dermatology 199, 231-236, 1999. 

The first line of treatment is usually the application of topical products, ranging from over-the-counter products to topical steroids. Emollients may be used to reduce dryness and scaling, as well as reducing the hyperproliferation associated with plaque psoriasis. The use of vitamin D analogues, tazarotene, dithranol or coal tar preparations aims to lessen or remove the patient s scaly plaques. However, excess use can irritate the skin and their use is not recommended for the more irritant forms of psoriasis. Tar baths and tar shampoos (containing coal tar) may help with managing the condition. Treatment, if nonirritating, should be continued for 4-6 weeks and thereafter assessed. Emollients... 

An emollient such as aqueous cream will reduce the inflammation. The proliferated cells may be eliminated by a dithranol (antimitotic) preparation applied accurately to the lesions (but not on the face) for 1 hour and removed begin with 0.1% and increase to 1%. Dithranol is available in cream bases or in Lassar s paste (the preparations are not interchangeable). It is used daily until the lesions have disappeared it is irritant to normal skin and stains skin and fabrics. Tar preparations are less effective alternatives, and are commonly used for psoriasis of the scalp. 

Coal tar preparations reduce itching and inflammation of the skin. These products have been used in combination with topical corticosteroids, as adjuncts so that lower strengths of corticosteroid can be used effectively, and in conjunction with ultraviolet fight therapies. These preparations are available as crude coal tar (1 % to 3%), or liquor carbonis detergens (5% to 20%). At times, coal tar is compounded by pharmacists into various concentrations and sometimes with topical corticosteroids. 

Coal tar preparations should not be used on acute oozing lesions, as this would result in stinging and irritation." " The strong odor of coal tar products and their staining of clothing are limiting factors. Patients can be instructed to use the product at bedtime and wash it off in the morning. In addition, folliculitis and photosensitivity have been reported. 

Coal Tar Products. In an industrial health survey of employees in nine coal tar plants in which coal tar creosote and coal tar were the main treatments used, renal effects, including protein and cells in the urine, were noted in 1-8% (3-34 of 452) of the employees examined (TOMA 1981). Nevertheless, no clear relationship could be established because exposure routes in addition to dermal were likely, such as inhalation and oral. Also, the ability to relate renal effects to coal tar exposure was further confounded by the possibility that the subjects were also exposed to other chemicals and cigarette smoke (TOMA 1981). A study performed by Wright et al. (1992b) evaluated the nephrotoxic effects of commercial coal tar preparation for the scalp. The preparation was applied to healthy human subjects either for 15 minutes,... 

Sixteen urine samples were collected from 4 male, nonsmoking psoriatic patients, undergoing treatment with the Goeckerman regimen (cutaneous application of coal tar based ointment, followed by exposure to UV irradiation) in the Dermatology Clinic of the University of Padua (Clonfero et al. 1989). Patient A was treated with pure coal tar for 1 day patients B, C, and D were treated with 4% coal tar based ointment for 2, 8, and 13 days, respectively. Body surface involved by psoriasis was 30, 40, 35, and 60% for patients A, B, C, and D, respectively. Total PAH (and pyrene) content of the two coal tar preparations was 28,800 (3,100) and 470 (104) ppm, respectively. The samples were collected at different times after the beginning of therapy (from 12 hours after the 1st application of coal tar to 72 hours after the last... 

Wright MC, Kaufhold A, Hevert F, et al. 1992a. [Investigations into possible nephrotoxicity of a coal tar preparation], Hautarzt43(8) 483-486. (German). 

Coal tar preparations are complex and variable mixtures of hydrocarbons that have cytostatic or antimitotic actions. Crude coal tar is the most effective, but few outpatients tolerate the mess and smell. In hospitals, coal tar is often combined with ultraviolet B (UVB) radiation. There are many proprietary preparations, which are more refined and therefore more acceptable to patients, but they are less effective. They are used as a creams, lotions, ointments and bath oils in concentrations from 1 to 12%. 

Coal tar preparations are less irritating to normal skin than dithranol, but can cause folliculitis. 

The client with psoriasis who is being treated with a tar preparation (Estar) calls the clinic nurse and reports an odor and staining of the client s shirt. Which action should the nurse implement ... 

Psoriasis is extremely difficult to treat, and tar preparations are an effective form of treatment and should not be discontinued because of expected effects. 

The hydrocarbon ("oil") fraction of a coal pyrolysis tar prepared by open column liquid chromatography (LC) was separated into 16 subfractions by a second LC procedure. Low voltage mass spectrometry (MS), infrared spectroscopy (IR), and proton (PMR) as well as carbon-13 nuclear magnetic resonance spectrometry (CMR) were performed on the first 13 subfractions. Computerized multivariate analysis procedures such as factor analysis followed by canonical correlation techniques were used to extract the overlapping information from the analytical data. Subsequent evaluation of the integrated analytical data revealed chemical information which could not have been obtained readily from the individual spectroscopic techniques. The approach described is generally applicable to multisource analytical data on pyrolysis oils and other complex mixtures. 

Zackheim HS (1978 a) Should therapeutic coal tar preparation be available over-the-counter Arch Dermatol 114 125-126... 

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