US 3794028 A
The invention disclosed provides a method of depilation in human mammal by injecting a dose of chemical depilatory solution into hair follicle such to permanently destroy hair growth at that location. Injection of the chemical depilatory solution may be effected by means of a hypodermic syringe for penetrating beneath the skin surface and for dispensing effective dosage amounts of the depilatory solution into the follicle.
Description (OCR text may contain errors)
[451 Feb. 26, 1974 United States 1191 Mueller et al.
450,032 4/1891 Perl 2,024,624 12/1935 Byrne............ 3,152,590 10/1964 Zurdo et METHOD FOR INJECTING CHEMICALS INTO THE PAPILLA FOR DEPILATION n w o r w R b w W n e r. P w hL .w r dm F r W0 mm mm, BA WW m We. rt P. A k .m ,m 6 .wsm 60c R 7 m T. 7 5 .Hn 4X 0 26% 1, um ,H mu uumm MO ll: .HG CL-N t 25 e 0 2 w m m RNAB7 E r m n e v M .1 6 7  Filed: Feb. 27, 1973 ABSTRACT  Appl. N0.: 336,222
Related [1.8. Application Data am m wm m 6 f d0 0 m m a 3 am dc wk on i w ml 3 S mm mm m nu .m t L wh .m RM To 6 2 s U A 8 6 5 7 o N L e f O t r a m H .Mm mm 3 a b U m m 9 C1 1 3 6 permanjection of the chemical depilatory solution may be effected by means of a hypodermic syringe for neath the skin surface and for di depilatory solution into hair follicle such to nently destroy hair growth at that location. I
penetrating bespensing effective osage amounts of the clepilatory solution into the follicle.
d 1.0 1 mm% m w ,moo 5 5 56.15 BAOB 8 38 20 2 lmlol ,7 6 2 l 7 one 62 RAW 2 .1 m h c U.r. 3 Ne m L .2 C mm .m U-mF HUM 555 [[1 330,715 Kennedy................................. 8/161 9 Claims, 1 Drawing Figure METHOD FOR llNJECTlNG CHEMICALS INTO THE PAPILLA FOR DEPILATION This application for U. S. letters Pat. is a continuation-in-part of application Ser. No. 175,068, filed Aug. 26, 1971, now abandoned.
The present invention relates to a method of depilation in human mammal and more particularly to depilation by injecting a dose of chemical depilatory solution into hair follicile beneath the skin surface.
In the present method, an appropriate depilatory solution containing hydrolyzing and/or reducing agents is disposed in direct contact with hair follicle by inserting a hypodermic syringe needle into the follicle and discharging an effective dosage of the depilatory solution.
Depilation is the well known process by which hair is removed by chemical degradation of the hair keratin. This is in contrast to epilation, wherein the hair is removed substantially intact.
One of the early depilatory compositions known in the prior art is that described in U.S. Pat. No. 707,955,
in which a composition consisting of sulphur, hypersulfite of soda and oil of turpentine is disclosed for use in weakening or permanently preventing growth of hair on the human body. This composition was applied to the skin where it remained for an appropriate time, after which the composition was removed in a suitable manner. Several applications were required at intervals of a few days to permanently destroy the hair roots or follicles.
A number of additional chemical depilatory compositions are also known to the art which destroy exposed portions of the hairshaft. Examples of such compositions include additives based on stannites, thioglycolates, alkaline sulfides of sodium and lithium; sulfides and sulph-hydrates of alkali and alkaline earth metals; dimethylamines and the like. Such depilatories are applied directly to the skin, and thus are able only to destroy hair at skin level.
Epilatory compositions, such as wax and rosin, are well known in the art. These compositions are applied commonly in combination with a bandage or pad for effecting hair removal. However, these compositions do not produce desired results of permanently destroying the hair root, thus preventing any further growth of the hair at that location.
A known method of permanently destroying the hair root is through electrolysis. ln electrolysis treatment, an instrument is used which includes a self-contained source of electric energy having a small needle of about mils. in diameter at one end. This needle is inserted through the skin alongside the hair to be removed and is maintained in contacting engagement with the papilla vascular connective process which nourishes the hair root. Contacting engagement is maintained for a predetermined number of seconds while the needle is electrically activated, after which the needle is with drawn. The hair is thus permanently destroyed and may be manually pulled out of location. The electrical energy working in the papilla permanently destroys any tendency for future growth of hair. This operation is continued hair-by-hair over the area of the skin desired to be treated.
The electrolytic process is based on decomposing the natural sodium chloride of the organism by the generation of current which accumulates soda within the follicle. The soda is the medium which destroys the hair and prevents any future growth at that location. This type of electrolytic treatment may cause pain to the person being treated when supplying electric energy inside the body.
Practice of the present invention will become more apparent by reference to the drawing wherein there is diagrammatically illustrated injection of a depilatory into the papilla by a hypodermic needle. Needle 5 of hypodermic syringe 6 is inserted through the skin 7 alongside hair 8, to be removed. The needle is inserted to a depth of about 3 to 4 mils. or a depth sufficient to insert a depilatory solution, such as soda, into follicle 9 such that the solution can reach the region of the papilla 10.
The extent of chemical reaction in the region of the papilla by the injected solution can be controlled by the concentration of the solution, having just enough selectively acting chemicals to finish the process of killing the hair-forming structure before being used up in chemical reaction. The chemistry of the reaction which takes place within the hair follicle to permanently kill the hair may be that described in detail hereinafter.
The papilla 10 has root contacts 11 which communicate with the body flood vessels to nourish the hair. It is in this region that the depilatory solution serves to permanently destroy the capacity of the hair to regrow. Thus, the depilatory solution serves not only to attack the hair fiber itself, but also the hair nourishment structure. Preferably, therefore, the injected solution is limited to the region of the papilla to permit the hair to be chemically attacked only at the end. Thus, the root end of the hair may be permanently killed by chemical action and then may be pulled out of the follicle 9 by the external hair portion. Pulling of the hair for removal may be by wiping or pulling action at some later time. Removal leaves little decomposed hair fiber within the papilla, as would necessarily result by the surface skin treatment methods and thus, limits the possibility of infection or inflammation.
In accordance with this invention, therefore, a number of advantages may be realized. For example, human hair may be completely converted to a soft, plastic mass which is easily removed from the skin by wiping or rinsing. Also, the present method permits non-toxic hair removal of the biological system and non-irritation of the skin.
A depilatory solution may be thus readily applied at each desired follicle through a hypodermic syringe economically, and with no pain such as is experienced by application of electrical energy.
In the chemical reaction, Keratin, the protein to which hair largely owes its characteristic physical properties, is particularly high in the sulphur containing amino acid, cystine (about 17%). Cystine, in turn, is linked chemically with other non-sulphur amino acids, including aspartic and glutamic acids. The disposition of the sulphur in the hair fiber becomes such as to form a sulphur-to-sulphur bridge between polypiptide chains (R) CH -S-S-CH -R. The kind and arrangement of these amino acid residues in juxtaposition to cystine seemingly govern the degree of protection or the vul- -nerability of the 8-8 (disulfide) linkage to attach by to prevent complete breakdown of all crosslinking disulfide bonds in a permanent waving process, it is the objective of chemical depilation to cleave sufficient S-S indiscriminately so that the hair will readily disintegrate for removal and the like linkages of the papilla are permanently destroyed. Under the influence of such different chemical agents as alkali, metal sulfides and sulfites, cyanides, amines, mercaptans and certain metal salts, the 8-5 bond in Keratin is affected; increasing osmotic pressure develops within the hair fiber which swells, loses its tensile strength, and generally deteriorates. A mass ofjelly-like consistency which can be easily removed by wiping or scraping is the final stage of the alkaline hydrolysis in the presence of a reducing agent. Both the outer layer (cuticle) and inner colorbearing layer (cortex) are disintegrated.
An example of the effect of alkali on 8-8 linkages is as follows:
Also, addition of organic bases, such as methylamines and dimethylamines, monoethanolamine, ethylenediamine, hydroxylamine, hydrazine, guanidine, aminoguanidine, and piperidine accelerate the dehairing effect of hydroxide suspensions. In general, alkaline degradation involves first the rupture of cystine linkages between main polypeptide chains, then progressing under more drastic treatment to hydrolyses of main polypeptide chains. The process is dependent on concentration of hydroxyl ions, temperature and time of reaction.
The disulfide linkges in Keratin can be broken by chemical reduction which is analogous to the reduction of cystine to cysteine:
R--SBR g 2R-SH Cystlne Cysteine This process is independent of R radical; reduction of 8-3 groupings in Keratin with aliphatic thiols, sulfides, bisulfites or cyanides; occurs in neutral, or better, in alkaline media through nucliophiltic attached radical displacement; or by an ionic mechanism.
The sulfides of Li, Na, K, CS, Mg, Ca, Sr, Ba, Al, As and Sn accelerate dehairing in the presence of calcium hydroxide suspensions. These depilatory formulations involve no unusual health hazard in skin surface treatments, and may be considered similarly safe when used in the present invention. The use of soda solution, for example. produces the effect caused by electrolysis, which has been used safely for many years. Moreover, use of the present method wherein the depilatory solution is placed into the hair follicle avoids the problem encountered when using cream or paste depilatories wherein the necessarily high pI-Is of the formulation hinders removal of hair below the skin by swelling the skin until openings of the hair follicles are constricted such that the alkali cannot get in and the hair root cannot get out.
The following examples are illustrative of the various chemical depilatory solutions that may be used in accordance with the teachings of the invention:
EXAMPLE I Percent By Ingredient Weight Potassium Sulfide l0 Propylene Glycol 11.5 Alcohol (Ethyl) 4 Water 73 Menthol 0.2 Perfume 1.0 Sodium Carboxymethyl cellulose (low viscosity) 0.3
EXAMPLE II Percent By Ingredient Weight Sodium Sulfide l0 Glycerin l0 Alcohol (Ethyl) 5 Water 73 Bcnzocaine 0.3 Menthol 0.2 Perfume l.5
EXAMPLE III Percent By Ingredient Weight Calcium 'lhioglyeolatc 8 Propyleneglyeol l l Carhowax 6000 (trademark for polyethylene glycols by Union Carbide Corp.) 4 Alcohol (Ethyl) 6 Water Perfume 1.0 Ammonium Hydroxide l0 EXAMPLE IV Percent By Ingredient Weight Dimethylamine 4.0 Glycerin 10 Water Tween 20 (trademark for polyoxyethylcne derivatives of fatty acid partial esters of hexitol'anhydrides By Atlas Chemical Co.) 5 Perfume 1.0
EXAMPLE V Percent By Ingredient Weight Sodium Sulfide l0 Sorhitol 9 Water 74 Atlas (1-2160 (trademark for a polyoxyethylcne oxypropylene stearatc containing emulsifier by Atlas Chemical Co.) Perfume l.0
EXAMPLE VI 10% by weight caustic soda solution EXAMPLE VII The present method was performed on a 53 year old caucasian volunteer. A section of the lateral left forearm (2 X 2 cm) was chemo-epilated in the following manner. Using an especially prepared micro-syringe, 1.0 mieroliter portion of a 0.1 N NaOH solution was injected into the base of the follicles through the follicular orifaee. The hair was then mechanically removed and the follicles were marked for later identification with a ball point pen. 24, 48 and 72 hours later, representative follicles were biopsied using a 2 mm dermal punch with local anesthesia. The specimens were then submitted for histological examination by serial sections and hematoxalin and eostin staining.
Patient discomfort and post-treatment reaction was minimal. The results of this test showed permanent, non-scarring epilation.
In practicing the present method, the depilatory solution may be administered by inserting a minute dose into each follicle to be destroyed by injection under the skin alongside the hair to reach the vicinity of the papilla with a hypodermic needle, as shown in the drawing. Typically, an effective dosage for use herein is about I to about 5 microliter quantities of 0.01 N and 0.1 N sodium hydroxide solution or the equivalent thereof. In this way, an economical, effective depilation method is provided which may utilize the skills of technicians now employing electrolysis for depilation, since the needles are inserted in the region of the papilla in a similar manner, but the sometimes painful step of introducing the electric current is eliminated.
The hair growth is, therefore, permanently destroyed in accordance with this invention by inserting a depilatory solution under the skin into the follicle in the region of the papilla with a hypodermic syringe. The needle of the syringe is immediately withdrawn after injecting the depilatory solution so that the method is faster than electrolysis aand more effective. Hairs may be removed after processing by pulling or wiping without the necessity of letting solutions be in contact with large areas of skin for long periods of time.
The chemicals used are selectively operable to attach the protein hair fiber of Keratin and to cause little reaction with other body tissue. In any event, the dosage is so small and may be so controlled by metering a given amount of a solution of given concentration that any reaction or damage to other tissue is confined to a small region adjacent the papilla.
Accordingly, the state of the depilation art is improved by the method of this invention with unexpectedadvantages of less pain, less time, less chance of inflammation and infection, and more effective permanent destruction of life of the hairs treated.
It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of this invention.
What is claimed is: 1. A method of permanently destroying hair growth within a hair follicle of a living mammal comprising the steps of inserting the needle end of a hypodermic syringe to disperse a minute dosage of chemical depilatory solution non-toxic to the biological system beneath the skin into the follicle alongside the hair to be destroyed, dispensing said chemical depilatory solution within the hair follicle to reach the vicinity of the papilla, and withdrawing said needle immediately after dispensing said solution.
2. The method as defined in claim 1, wherein in said insertion step the needle end of said hypodermic syringe is inserted to a depth of about 3 to 4 mm. within said hair follicle.
3. The method as defined in claim 2, wherein in said insertion step the needle end of said hypodermic syringe enters the region of the papilla.
4. A method of depilation in human mammal comprising the steps of,
choosing as a dose a controlled amount of a selectively acting depilatory chemical solution non-toxic to the biological system of the mammal for adequately reacting with the hair forming structure to destroy it,
injecting the dose of depilatory solution into the hair follicle beneath the skin surface, and
permitting said solution to remain in the follicle until the chemical reaction with the hair forming structure is completed, the controlled quantity thereby limiting the possibility of inflammation.
5. The method defined in claim 4, wherein the solution is a soda solution.
6. The method defined in claim 4, wherein the solution is a chemical that reacts with Keratin.
7. The method defined in claim 4, wherein the depth of insertion is controlled and the solution is metered in amount and strength to effect chemical reaction only in'a limited region about the papilla.
8. The method defined in claim 4, wherein the solution is about 0.01 N to about 0.10 N sodium hydroxide solution.
9. The method defined in claim 4 wherein the amount of solution injected is about 1 to about 5 microliters.