Depilatory – Depilatories – Epilatoires,are preparations in powder or cream form used to remove and clear hair from the body.Depilationon the other hand, is the process of eliminating hair through chemical degradation (breakdown).
Epilation, however, is the removal of hair from the root. This is applied by plucking, electrical devices, X-rays, and thallium.
Among depilatory substances, alkali and alkaline earth sulfides have been known for 6,000 years. Various depilatories were used, especially in civilizations along the Mediterranean coast. The earliest depilatory formula was found in the Ebers Papyrus.
A classic formula, Turkish Rusma (Rusma Turcorum, Rusma des Turcs), contains calcium oxide 8 parts, orpiment 1 part (Arsenic trisulfide)=(As2S3 ) along with a very small amount of egg white and soda lye.In depilatories;1- A strong reducing agent,
2- Strongly alkaline conditions (pH 10),
3- Aqueous conditions are required.
In an alkaline medium, hair dissolves easily. The duration is 2–5 minutes. The water content in the paste should be 40–50%.Desired properties of a preparation used for the chemical removal of hair;1- It should coat the hair in a soft, plastic-like layer, and this coating should be easily removed by washing or wiping.
2- It must be colorless and non-staining.
3- It must not irritate the skin.
4- It must be stable and not easily deteriorate.Rp
Sodium sulfide
Calcium hydroxide / aa 2 g
Glycerin 8 g
Methyl cellulose (150 cp) 2 g
Water 50 g
Talc 5 g
Ingredients in the formula
Sodium sulfide – Sodii sulphur – Sulfure de sodium;Known as zirnik in industry, this substance is prepared by gently heating sodium carbonate with sulfur. It has a colorless crystalline appearance, an alkaline character, and is highly soluble in water. It has been used in doses of 0.02-0.05 g in bronchitis, and externally as a bath or lotion in certain skin diseases and rheumatism.
In this formula, upon the addition of water to sodium sulfide: NaS+H2O>NaHS+NaOH is formed. Its 2% solution exhibits a depilatory effect in 6-7 minutes at pH 12.Calcium hydroxide – Calcii hydroxidum – Calcium hydroxide;
Calcium hydroxide, is a chemical compound obtained by adding water to quicklime. It is found as a fine white crystalline powder. It is a strong alkali that gives a paste-like appearance when mixed with water. Its traditional name is slaked lime or hydrated lime. It is insoluble in alcohol and sparingly soluble in water. It is soluble in glycerin. If heated up to 512 degrees, it decomposes into calcium oxide and water. It has been used as an excipient to impart alkaline properties to the formula.Glycerol – Glycerine – Glycerolum – Glycerol (85%)Glycerin is a clear, colorless or very pale, hygroscopic, syrupy liquid that is odorless or practically odorless, with a sweet taste. It is miscible with water and alcohol; slightly soluble in acetone; practically insoluble in chloroform, ether, fixed oils, and essential oils. Its aqueous solutions give a neutral reaction to litmus. According to the United States Pharmacopeia (USP), the pH of Glycerin Oral Solution, USP is between 5.5 and 7.5. Strong oxidizing agents form explosive mixtures with glycerin.Methylcellulose – Methylcellulose – Cellulose methyl etherMethylcellulose is an excipient frequently used in oral and topical pharmaceutical preparations. In tablet formulations, low or medium viscosity grades are used as binders, while high viscosity grades are used as disintegrants. In sustained-release tablet formulations, it functions as a matrix material and as a coating agent for masking the unpleasant tastes of core tablets or protecting core tablets from moisture prior to sugar coating. In addition, it is useful as a viscosity-increasing agent in suspension formulations and as an emulsifier in oil-containing formulations. In topically applied cream and gel-type formulations, its high-viscosity grades are utilized as thickeners. Methylcellulose is a long-chain substituted cellulose derivative. It occurs as a white or yellowish-white, hygroscopic, odorless, fibrous granule or powder. It is practically insoluble in hot water, anhydrous alcohol, acetone, chloroform, ether, and toluene; it dissolves in cold water, forming a colloidal dispersion. It also dissolves in glacial acetic acid and in equal volumes of an alcohol-chloroform mixture. The pH of a 1% aqueous solution is between 5.5 and 8.0.
Methylcellulose solutions are stable at room temperature between pH 3 and 11. However, its viscosity decreases below pH 3. When its solutions are heated, the viscosity decreases until gelation occurs. Methylcellulose has been reported to show incompatibility with chlorocresol, mercuric chloride, resorcinol, tannic acid, silver nitrate, cetylpyridinium chloride, para-aminobenzoic acid, hydroxybenzoates, and phenol.Talc-Talcum-Purified Talc:Talc is a natural hydrated magnesium silicate. Its approximate chemical formula is ‘Mg6Si2O54OH4’. It may contain varying amounts of aluminum silicate and iron. It is a very fine, light, homogeneous, white or off-white or grayish-white, odorless crystalline powder. When it comes into contact with the skin, it readily adheres to the contact surface. Purified talc must be free of microscopic asbestos particles. Talc is practically insoluble in water, mineral acids, and dilute solutions of alkali hydroxides.Modus operandi = Method of preparationIn a beaker, heat 1/3 of the required amount of water to around 900 C. Sprinkle the methyl cellulose onto it and let it stand for half an hour. Then add the remaining water and mix. Thoroughly pulverize the sodium sulfide in a mortar and mix with calcium hydroxide. Then, gradually add the fully swelled methyl cellulose gel into this mixture while stirring. Add the glycerin and mix everything thoroughly. Place into an ointment jar and label appropriately. Although not included in the formula, fragrances such as camphor, eucalyptol, and geraniol can be used to mask the sulfide odor.
Remember that the gel should be removed from the body by washing 15-20 minutes after application.
Wishing you a good week …ReferencesCosmetic Formulas: Prof. Dr. Kasım Cemal Güven
Gazi University Department of Pharmaceutical Technology Lecture Notes (1981)Exp. Pharm. Ahmet Nezihi Pekcan
Pekcan Pharmacy – Konya
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Tel: (332) 3520657
http://www.majistralformul.com/
