Salicylate Lotion

00 11 Propylene glycol, diazolidinyl urea, methylparaben, and propylparaben 10.00 

Heat to 80°C add this part to previous part slowly, using good mechanical mixing. 

Allow to cool while mixing to 40°C and then add item 11 cool to 30°C and fill. 

Handbook of Pharmaceutical Manufacturing Formulations Semisolid Products 

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Benzyl Chloride. Benzyl chloride is manufactured by high temperature free-radical chlorination of toluene. The yield of benzyl chloride is maximized by use of excess toluene in the feed. More than half of the benzyl chloride produced is converted by butyl benzyl phthalate by reaction with monosodium butyl phthalate. The remainder is hydrolyzed to benzyl alcohol, which is converted to ahphatic esters for use in soaps, perfume, and davors. Benzyl salicylate is used as a sunscreen in lotions and creams. By-product benzal chloride can be converted to benzaldehyde, which is also produced directiy by oxidation of toluene and as a by-product during formation of benzoic acid. By-product ben zotrichl oride is not hydrolyzed to make benzoic acid but is allowed to react with benzoic acid to yield benzoyl chloride. 

As of 1991 in the United States, OTC antiacne preparations may contain only a few active dmgs, for example, sulfur [7704-34-9] resorcinol acetate [102-29-4], resorcinol [108-46-3], salicylic acid [69-72-7], and some combinations (52). OTC anti-acne constituents maybe included in a variety of conventional cosmetic preparations, which then become OTC dmgs. These include lotions, creams, solutions, facial makeups, facial cleansers (including abrasive cleansers), and astringents. Products must contain the specified dmgs at the designated concentrations. Compositions of antiacne products have beenpubhshed (53). 

Selenium sulphide, coal tar, ketoconazole and salicylic acid are agents that can be used in dandruff. Permethrin is an insecticide indicated in the eradication of head lice. Permethrin is available as alcoholic or aqueous lotions. 

The influence of a cream containing 20% glycerin and its vehicle on skin barrier properties has been investigated. Recent studies have shown that polymers offer several advantages and can be used in skin care products. Phase diagrams were determined for lactic and isohexanoic hydroxy acids as well as salicylic acid with water, a nonionic surfactant and a paraffinic oil, to outline the influence of hydroxy acids on the structure in a model for a skin lotion. The results showed the influence of the acid to be similar to that of the oil but that the difference in chain length between the two alpha acids had only insignificant influence. The results are discussed from two aspects the structures involved in the lotion as applied, and the action of the lotion residue on the skin after the evaporation of the water. 

Figure 2.5 Reported concentrations of various PPCPs in Wastewater effluents by several research groups. On the x axis are respective PPCPs that are primarily cosmetics (1 = HHCB, 2 = AHTN, 3 = acetophenone, 4 = camphor, 5 = isobomeol, 6 = skatol, 7 = celestolide, i.e., AHMI, 8 = Phantolide, i.e., AHMI), the lotion ingredient (9 = methyl salicylate), two disinfectants (10 = triclosan and 11 = trilocarban), antihypertensive (12 = dehydronifedipine, 13 = diltiazem, 14 = bezafibrate, and 15 = gemfibrozil), analgesics and anti-inflammatories (16 = naproxen, 17 = ibuprofen, 18 = codeine), antimicrobials (19 = chlortetracycline, 20 = erythromycin, 21 = novobiocin, 22 = oxytetracycline, 23 = sulfamethaxazole, 24 = thiabendazole, 25 = trimethoprim), anxiolytic sedative (26 = carbamazepine), antidiabetic (27 = metaformin), reproductive (28 = 17(3 estradiol, 29 = 17a-ethinyl estradiol), GIT (30 = cimetidine, 31 = ranitidine), and respiratory (32 = Albuterol). The concentrations were compiled from Boyd et al. (2003), Gagne et al. (2006), Glassmeyer et al. (2005), Halden and Pauli (2005), Huang and Sedlak (2001), Ricking et al. (2003), and Temes et al. (2003).

Salicylic acid USP, EP, and other pharmacopeia grades are used medically as antiseptic, disinfectant, antifungal, and keratolytic agents. Salicylic acid is formulated in lotion or ointment formulations for the treatment of dandruff, eczema, psoriasis, and various parasitic skin diseases. Because the keratolytic property of this aromatic acid has use in the safe removal of dead skin cells from the surface of healthy skin, the acid is used in concentrated salicylic acid solutions or suspensions to remove warts and corns. In more dilute form, salicylic acid preparations have found use in dandruff and eczema treatment. Salicylic acid has been considered and found effective by the Advisory Committees to the FDA in various over-the-counter (OTC) drug regulated uses. Among these are acne products, dermatitis, dry skin, dandruff and psoriasis products, and foot care products (24). 

Salicylamide [65-45-2] is prepared by the reaction of methyl salicylate with ammonia. Salicylamide has mild analgesic, antiinflammatory, and antipyretic properties. Salicylamide is unlike other salicylates in that it causes sedation and central nervous system depression. Salicylamide is not hydrolyzed to salicylate and its action depends on the entire molecule. Salicylamide has been useful for protection against mildew and fungus in a variety of soaps, salves, lotions, and oils. The May 1996 price was 8.00/kg (18). 

Perfumes, Flavors, Cosmetics, and Soap. Many naturally occurring esters in essential oils and some synthetic esters are important fragrance and flavor compounds (61,62). They are used in perfumes, flavors, cosmetics, soaps, deteigents, and air fresheners. Benzyl, butyl, ethyl, methyl, and phenyl esters of benzoic acid are used as flavors, perfumes, and food preservatives. Glyceryl 4-aminobenzoate [13644-7] and 2-ethylhexyl 4-dimethylaminobenzoate [21245-02-3] are used in cosmetic sunscreen preparations. Alkyl esters of 4-hydroxybenzoic acid, called parabens, have been used under various names for fungus infections of the skin, and as preservatives in lotions and creams (101). Soap and cosmetic fragrances use large amounts of amyl and benzyl salicylate. Benzyl salicylate [118-58-1] is also used in deodorant sprays. 2-Ethylhexyl salicylate [118-60-5] and 2-ethylhexyl 4-methoxycinnamate [5466-77-3] are used in sunscreen formulations (102). 

The presence of certain metals such as iron, particularly in the presence of water, can act as a catalyst for many types of chemical reaction including oxidation, and iron can itself form highly colored reddish-brown complexes with many materials. A common test for the presence of iron in essential oils such as patchouli, where it can occur as a result of the distillation process being carried out in nonstainless steel equipment, is to mix the oil with benzyl salicylate. If iron is present, a reddish color develops after a few moments. Fortunately iron can quite easily be removed by treatment with citric, tartaric, or oxalic acids, with which it forms stable sequestered complexes. Compounds that show this type of discoloration can sometimes be recovered in this way if not too old, whereas products containing water (which may be the source of the iron contamination), such as alcoholic lotions, will usually show too much odor deterioration, by the time the discoloration has developed, to make recovery possible. 

Salicylic acid (1) is not employed internally as an analgesic due to its local irritating effect on the gastrointestinal tract. It is employed externally on the skin, where it exerts a slight antiseptic action and a marked keratolytic action. The latter property makes salicylic acid a beneficial agent in the local treatment of warts, corns, fungous infections, and certain forms of eczematoid dermatitis. Tissues cells swell, softer, and ultimately desquamate. Salicylic acid is applied as a 2 to 20% concentration in collodion, lotions, or ointments, and as a 10 to 40% concentration in plasters. Salicylic acid plaster is used for the destructive effect of salicylic acid on hardened, keratinized tissue. The so-called corn plaster are typical. 

Many of the models are based on experiments in which permeants were applied in aqueous solution and, therefore, their value in prediction of permeation from actual formulations applied under in-use conditions is compromised. For example, whilst the predicted Kp for ni-trosodiethanolamine is 1.5 X 10-4 cm/h, the experimentally determined value from isopropyl myristate (IPM) was 3.5 X 10-3 cm/h (Franz et al. 1993). The predicted value for octyl salicylate is 1.35 X 10-7 cm/h, whilst the experimental values from a hydroalcoholic lotion were 4.7 X 10 6 cm/h (infinite dose) and 6.6 X 10 7 cm/h (finite dose) and from an oil-in-water... 

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