Cooling ointment

Lipophilic cream Cream W/o cream Cooling ointment ENA (Table 12.31), Hydrophobic cream base DAC (Table 12.32)... 

Smell correctors are only exceptionally added to dermatological preparations because of possible allergic reactions. Usually volatile oils are being used. The risk of an allergic reaction is supposed to be small for rose oil and lavender oil. An example of a smell corrector in a skin preparation is rose oil in a cooling ointment (Table 12.31). 

A specific hydrophobic cream base is Cooling Ointment. A cooling ointment should be unstable, separate on the skin and cool the skin through evaporation of water. 

The Cooling Ointment given in Table 12.30 does not contain any physical stabilisers. The aqueous phase is only physically bound. It is not very suitable for the addition of active substances that affect the physical stability such as lauromacrogol 400, coal tar solution or urea. After a relatively short time water can separate. Only a limited number of substances can be added often in a low concentration. Solid substances such as glucocorticosteroids, salicylic acid... 

Table 12.30 Cooling Ointment DAB [48] Table 12.32 Hydrophobic Cream Base DAC [50] ...

Another cooling ointment is depicted in Table 12.31. The name Cooling Ointment is actually not correct anymore for that formulation. In the course of time different formulations have been used. In practice the physical instability was not appreciated anymore because it made the addition of active substances impossible. The formulation is too stable to be a good cooling ointment, because it contains glycerol mono-oleate, a w/o surfactant. But addition of active substances is possible and this Cooling Ointment functions firstly as preservative free cream base. 

Although cooling ointments are w/o systems, they are microbiologically vulnerable to bacteria, fungi and yeasts (see Sect. 12.5.3.5). But the preservation is often not desired. Cooling ointments are regarded as bases that are well tolerated on the skin and preservatives may cause sensitisation and irritation. Typically they are not preserved and thus the shelf life has to be shortened. 

After heating to 50 °C in a water bath, the sample was cooled to below room temperature and filtered. The residue was washed with two 5-mL portions of CCI4, and the combined filtrates were collected in a 25-mL volumetric flask. After adding 2.00 mL of the internal standard solution, the contents of the flask were diluted to volume with CCI4. Analysis of an approximately 2- tL sample gave LfD signals of f3.5 for the terpene hydrate and 24.9 for the camphor. Report the %w/w camphor in the analgesic ointment. 

Once the desired frost is achieved, the skin can be rinsed off with water, or cooled down with cool wet compresses which are applied to the skin. The wet compresses can provide a welcome relief to the burning induced by the peel. Unlike glycolic peels the water does not neutralize the peel, as the frosting indicates the end-point of the reaction rather, it dilutes any excess TCA. The compresses can be repeated several times until the burning sensation has subsided. Subsequently, a layer of ointment such as plain petrolatum or Aquaphor is applied and post-peel instructions and what to expect are reviewed with the patient prior to discharge to home. 

Elder leaves contain the alkaloid sambucine, a precursor of hydrocyanic acid, which is somewhat toxic. Thus, the leaves are used only topically in ointments for sprains or bruises. Bruised leaves can be rubbed on the body or worn under a hat to prevent being pestered by insects. Cooled strained leaf tea can be applied to plants to discourage aphids. 

Melt the stearyl alcohol, white wax, and cholesterol (steam bath). Add the petrolatum and continue heating until a liquid melt is formed. Cool with stirring until congealed. III. Water-washable ointment (hydrophilic ointment, USP) White petrolatum 25% (w/w)... 

Melt the PG 4000 and add the liquid PG 400. Cool with stirring until congealed. Y. Cream base, w/o (rose water ointment, NF 14) Oleaginous phase Spermaceti 12.5%... 

Methyl salicylate Disperse ointment in 10 ml chloroform, heat to 50°C, cooled, filtered 49... 

Stearyl Alcohol Reduction of ethyl stearate in the presence of lithium aluminum hydride yields stearyl alcohol, which contains not less than 90% of 1-octadecanol. It is available as flakes or granules which are white in color and possesses a characteristic odor. It is insoluble in water and melts at 55-60 °C. Stearyl alcohol has stiffening, viscosity-enhancing, and emollient properties and hence is used in the preparation of hydrophobic ointments and creams. Its weak emulsifying properties help in improving the water-holding capacity of ointments. Hypersensitivity reactions are sometimes observed due to the presence of some minor impurities. Stearyl alcohol preparations are compatible with acids and alkalis and are preserved in well-closed containers in a cool and dry place [6]. 

Metal Particles This test is required only for ophthalmic ointments. The presence of metal particles will irritate the corneal or conjunctival surfaces of the eye. It is performed using 10 ointment tubes. The content from each tube is completely removed onto a clean 60-mm-diameter petridish which possesses a flat bottom. The lid is closed and the product is heated at 85 °C for 2 h. Once the product is melted and distributed uniformly, it is cooled to room temperature. The lid is removed after solidification. The bottom surface is then viewed through an optical microscope at 30x magnification. The viewing surface is illuminated using an external light source positioned at 45 ° on the top. The entire bottom surface of the ointment is examined, and the number of particles 50 pm or above are counted using a calibrated eyepiece micrometer. The USP recommends that the number of such particles in 10 tubes should not exceed 50, with not more than 8 particles in any individual tube. If these limits are not met, the test is repeated with an additional 20 tubes. In this case, the total number of particles in 30 tubes should not exceed 150, and not more than 3 tubes are allowed to contain more than 8 particles [15]. 

Contact dermatitis may resolve without treatment within days but may take up to 3 weeks in allergic cases. In contrast, in toxic cases resolution may take 3 to 6 weeks. Avoidance of the offending agent is the first step in the treatment of contact dermatitis, with emphasis given to decreasing rubbing and scratching. Snpportive therapy includes cool compresses. In addition, application of topical steroid ointment or cream preceded by cool compresses temporarily relieves symptoms. Steroid use should be limited to 5 to 10 days due to the risk of tachyphylaxis, atrophy of the skin, and increased risk of infection. 

Ointments are prepared by melting together the active ingredient with a base, such as petroleum derivative or wax. The powdered drug components are added while stirring and the mixture is cooled. The product then is passed through a roller mill to achieve the particle size range desired for the dispersed solid. 

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