FIELD OF INVENTION
[001] The present disclosure broadly relates to the field of personal hygiene and
particularly relates to a skin-friendly soap composition having a neutral pH.
BACKGROUND OF INVENTION
[002] Skin is the largest organ in the human body and acts as the first line of defense against the external environment. Hence, retaining the skin barrier property is the biggest challenge. However, one of the key step to protect the skin barrier property is to maintain the pH of skin. Generally, the pH of skin is slightly acidic (pH= 5.0 - 6.0 (pH and Skin Care, 2007, Chapter 3, The skin pH in cutaneous physiology, p.no:15- 23) and is maintained by the presence of lactic acid, certain amino acids and also the composition of sebum lipids and proteins of the corneal layer of epidermis. The external aggressors such as pollution, temperature, and harsh chemicals tend to alter the pH of the skin by creating an imbalance between various factors contributing to skin pH and thus, rendering skin vulnerable to infections and other undesired affects.
[003] Generally, consumers are using various cosmetic products in order to maintain the skin health. However, some of the products like soaps may disturb the skin barrier protection by diminishing the skin lipids due to the alkaline nature of soaps. Attempts have been made in the past to address this issue through introduction of products like syndet bars, amino acid based bars that maintain the soap bar pH ranges between 5.5 and 7.0. Normally these products contain quite higher amount mild surfactants. This invariably adds to the cost component. [004] US patent 5529714 describes adjustment of pH of the bar by incorporating mono carboxylic acids, citric acid while maintaining the transparency of the bar. [005] Chinese patent CN 104312747 describes amino acid based transparent solid bar with pH below 7.0.
[006] There still remains a need for a soap bar composition with near neutral or less pH with desired sensorials and which also offers cost advantage.

SUMMARY OF THE INVENTION
[007] In an aspect of the present invention, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; and (b) at least one alkyl dicarboxylic acid, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154.
[008] In an aspect of the present invention, there is provided a process for preparing the transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; and (b) at least one alkyl dicarboxylic acid, said process comprising: (i) obtaining at least one alkali metal salt of C8-C18 fatty acid; (ii) obtaining at least one alkyl dicarboxylic acid; and (iii) contacting the at least one alkali metal salt of C8-C18 fatty acid, and the at least one alkyl dicarboxylic acid to obtain the transparent neutral soap composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154.
[009] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Those skilled in the art will be aware that the present disclosure is subject to
variations and modifications other than those specifically described. It is to be
understood that the present disclosure includes all such variations and
modifications. The disclosure also includes all such steps, features, compositions,
and compounds referred to or indicated in this specification, individually or
collectively, and any and all combinations of any or more of such steps or features.
Definitions
[0011] For convenience, before further description of the present disclosure,
certain terms employed in the specification, and examples are delineated here.

These definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the
meanings recognized and known to those of skill in the art, however, for
convenience and completeness, particular terms and their meanings are set forth
below.
[0012] The articles “a”, “an” and “the” are used to refer to one or to more than one
(i.e., to at least one) of the grammatical object of the article.
[0013] The terms “comprise” and “comprising” are used in the inclusive, open
sense, meaning that additional elements may be included. It is not intended to be
construed as “consists of only”.
[0014] Throughout this specification, unless the context requires otherwise the
word “comprise”, and variations such as “comprises” and “comprising”, will be
understood to imply the inclusion of a stated element or step or group of element or
steps but not the exclusion of any other element or step or group of element or
steps.
[0015] For the purposes of the present disclosure, the term "transparent soap"
refers to a one-quarter inch soap section through which a person having 20/20
vision can read 14-point boldface type. This term is not restricted to those soaps
which are clear or colorless because it is often desirable to add color to transparent
soap.
[0016] For the purposes of the present disclosure, the term ‘neutral’ has been used
to describe soap composition having a pH value in the range of 7.0 to 8.5.
[0017] The term “including” is used to mean “including but not limited to”.
“Including” and “including but not limited to” are used interchangeably.
[0018] For the purposes of the present disclosure, alkyl dicarboxylic acid refers to
acids with chain length ranging between C5- C18.
[0019] Unless defined otherwise, all technical and scientific terms used herein have
the same meaning as commonly understood by one of ordinary skill in the art to
which this disclosure belongs. Although any methods and materials similar or
equivalent to those described herein can be used in the practice or testing of the

disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.
[0020] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally-equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein.
[0021] To counter the problems of the harshness caused by the conventional bathing soaps, it would be desirable to adjust the pH of the soap close to that of the pH of skin, thus eliminating the drastic sensitizing effects caused by the use of alkaline soaps. The adjustment in the pH of soap containing bath oil retards the removal of valuable skin oils. It also leads to replenishment of skin oils when applied over a longer time period. Furthermore, for commercial acceptance, transparent soaps must retain all the quality characteristics of conventional, and opaque soap (such as good lather, hardness, mildness, minimum sluffing and the like). It is even desirable that these products must remain transparent under normal use for extended periods of time, while being economically viable.
[0022] A potential method or approach to reduce the pH of syndet soap is, to have sufficient amount of free fatty acid in the soap composition. But unfortunately, the same approach cannot be adapted to transparent soaps, because free fatty acids will quench the transparency as well as affect the bar structure. The present disclosure discloses a soap composition which can be used to prepare both colored and clear transparent soaps with a desirable neutral pH and key attributes of soap bar. The present disclosure discloses a soap composition comprising at least one alkali metal salt of C8-C18 fatty acid; and at least one alkyl dicarboxylic acid, wherein the at least one alkyl dicarboxylic acid to the at least one alkali metal salt of C8-C18 fatty acid w/w ratio is in the range of 1:0.0037 - 1:0.154. The C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof. The at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof. The composition has a pH value in the range of 7.0

to 8.5. Preferably, the soap composition has a pH value in the range of 7.5 to 8.5. The method for preparing the soap composition has also been disclosed in the present disclosure.
[0023] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; and (b) at least one alkyl dicarboxylic acid, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154. In another embodiment of the present disclosure, the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.010 - 1:0.10. In yet another embodiment of the present disclosure, the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.040 - 1:0.070. [0024] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof. In another embodiment of the present disclosure, the C8-C18 fatty acid is a combination of coconut fatty acid, lauric acid and hysteric acid.
[0025] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid is a compound of Structure I:
having n in the range of 3-16, and total carbon chain in the range of C5 to C18. In another embodiment of the present disclosure, the at least one alkyl dicarboxylic acid is a compound of Structure I having n in the range of 4-8, and the total carbon chain in the range of C5 to C10.

[0026] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof. In another embodiment of the present disclosure, the at least one alkyl dicarboxylic acid is suberic acid.
[0027] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof, and the at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof. In another embodiment of the present disclosure, the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, lauric acid, hysteric acid, and combinations thereof, and the at least one alkyl dicarboxylic acid is suberic acid.
[0028] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkali metal is selected from the group consisting of sodium, potassium, and combinations thereof. In another embodiment of the present disclosure, the at least one alkali metal is sodium.
[0029] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkali metal salt of C8-C18 fatty acid has a weight percentage in the range of 12%-27% with respect to the soap composition. In another embodiment of the present disclosure, the least one alkali metal salt of C8-C18 fatty acid has a weight percentage in the range of 12%-25% with respect to the soap composition.
[0030] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof, and the at least one alkali

metal salt of C8-C18 fatty acid has a weight percentage in the range of 12%-27% with respect to the soap composition.
[0031] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.1%-2.0% with respect to the soap composition. In another embodiment of the present disclosure, the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.50%-1.50% with respect to the soap composition. In yet another embodiment of the present disclosure, the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.50%-0.80% with respect to the soap composition.
[0032] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof, the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.1%-2.0% with respect to the soap composition.
[0033] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; and (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154. In another embodiment of the present disclosure, the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.010 - 1:0.10. In yet another embodiment of the present disclosure, the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.040 - 1:0.070.
[0034] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; and (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and

combinations thereof, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154, and wherein the at least one carboxylic acid is selected from the group consisting of C8-C18 mono carboxylic fatty acid. In another embodiment of the present disclosure, the at least one carboxylic acid is oxa acid. In another embodiment of the present disclosure, the at least one carboxylic acid is a combination of C8-C18 mono carboxylic fatty acid and oxa acid.
[0035] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; and (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154, and wherein the at least one carboxylic acid has a weight percentage in the range of 0.1%-4.5% with respect to the soap composition. In another embodiment of the present disclosure, the at least one carboxylic acid has a weight percentage in the range of 0.5%-4.0% with respect to the soap composition. In yet another embodiment of the present disclosure, the at least one carboxylic acid has a weight percentage in the range of 1.0%-3.0% with respect to the soap composition. [0036] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; and (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154, and wherein the C8-C18 mono carboxylic fatty acid is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and combinations thereof, and the oxa acid is selected from the group consisting of diglycolic acid, polyglycol diacid, dioxaoctanedioic acid, trioxaundecanedioic acid and, combinations thereof. In another embodiment of the present disclosure, the

C8-C18 mono carboxylic fatty acid is lauric acid, and the oxa acid is polyglycol diacid, and the polyglycol diacid is Poly(ethylene glycol)bis(carboxymethyl)ether. [0037] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the diglycolic acid is a compound
[0038] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition;

(h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (i) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154. In another embodiment of the present disclosure, the at least one surfactant has a weight percentage in the range of 15%-20% with respect to the composition, the at least one humectant has a weight percentage in the range of 45%-60% with respect to the composition, and the at least one electrolyte has a weight percentage in the range of 1.6%-2.9% with respect to the composition, and water having a weight percentage in the range of 20%-23% with respect to the composition.
[0039] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (i) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154, and wherein the at least one surfactant is selected from the group consisting of sodium laureth sulfate, decyl glucoside, sodium lauryl sulfate, disodium laureth sulfosuccinate, sodium cocoyl isethionate, sodium lauryl sarcosinate, sodium cocoyl glutamate, sodium cocoyl glycinate, coco glucoside, lauryl glucoside, sodium lauroamphoacetate, and combinations thereof; the at least one humectant is selected from the group consisting of sorbitol,

glycerine, propylene glycol, dipropylene glycol, butylene glycol, and combinations thereof; the at least one electrolyte is selected from the group consisting of sodium chloride, sodium sulfate, and combinations thereof; the at least one chelating agent is selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), etidronic acid, and combinations thereof; the at least one antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and combinations thereof.
[0040] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (i) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154, and wherein the at least one surfactant is a combination of sodium laureth sulfate and decyl glucoside.
[0041] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of

1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (i) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154, and wherein the at least one humectant is a combination of sorbitol, glycerine and propylene glycol.
[0042] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (i) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154, and wherein the at least one electrolyte is sodium chloride.
[0043] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the

composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; (i) fragrance; (j) color; and (k) water having a weight percentage in the range of 17%-25% with respect to the composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154.
[0044] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the composition has a pH value in the range of 7.0-8.5. In another embodiment of the present disclosure, the composition has a pH value in the range of 7.5-8.5. In yet another embodiment of the present disclosure, the composition has a pH value in the range of 7.8-8.2. [0045] In an embodiment of the present disclosure, there is provided a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; and (b) at least one alkyl dicarboxylic acid, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154, and wherein the composition has a pH value in the range of 7.0-8.5. In another embodiment of the present disclosure, the composition has a pH value in the range of 7.5-8.5.
[0046] In an embodiment of the present disclosure, there is provided a process for preparing the transparent neutral soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; and (b) at least one alkyl dicarboxylic acid, said process comprising: (i) obtaining at least one alkali metal salt of C8-C18 fatty acid; (ii) obtaining at least one alkyl dicarboxylic acid; and (iii) contacting the at least one alkali metal salt of C8-C18 fatty acid, and the at least one alkyl dicarboxylic acid to obtain the transparent neutral soap composition, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154.
[0047] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition comprising: (a) at least one alkali metal

salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (g) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (h) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; (i) fragrance; (j) color; and (k) water having a weight percentage in the range of 17%-25% with respect to the composition, said process comprising (i) obtaining the at least one alkali metal salt of C8-C18 fatty acid; (ii) obtaining the at least one alkyl dicarboxylic acid; (iii) obtaining the at least one carboxylic acid; (iv) obtaining the at least one surfactant; (v) obtaining the at least one humectant; (vi) obtaining the at least one electrolyte; (vii) obtaining the at least one chelating agent; (viii) obtaining the at least one antioxidant; (ix) obtaining color; (x) obtaining water; (xi) obtaining fragrance; and (xii) contacting the at least one alkali metal salt of C8-C18 fatty acid, the at least one alkyl dicarboxylic acid, the at least one carboxylic acid, the at least one surfactant, the at least one humectant, the at least one electrolyte, the at least one chelating agent, the at least one antioxidant, color, fragrance, and water to obtain the transparent soap, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154, and wherein the composition has a pH value in the range of 7.0-8.5. [0048] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition comprising: (a) at least one alkali metal salt of C8-C18 fatty acid; (b) at least one alkyl dicarboxylic acid; (c) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (d) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (e) at least one humectant having a weight percentage in the range of 37%-67% with respect to

the composition; (f) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; and (g) water having a weight percentage in the range of 17%-25% with respect to the composition, said process comprising (i) obtaining the at least one alkali metal salt of C8-C18 fatty acid; (ii) obtaining the at least one alkyl dicarboxylic acid; (iii) obtaining the at least one carboxylic acid; (iv) obtaining the at least one surfactant; (v) obtaining the at least one humectant; (vi) obtaining the at least one electrolyte; (vii) obtaining water; and (xii) contacting the at least one alkali metal salt of C8-C18 fatty acid, the at least one alkyl dicarboxylic acid, the at least one carboxylic acid, the at least one surfactant, the at least one humectant, the at least one electrolyte, and water to obtain the transparent soap, wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 -1:0.154, and wherein the composition has a pH value in the range of 7.0-8.5. [0049] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof. [0050] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof.
[0051] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one alkali metal is selected from the group consisting of sodium, potassium, and combinations thereof.
[0052] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the least one alkali metal salt of C8-C18 fatty acid has a weight percentage in the range of 12%-27% with respect to the soap composition.

[0053] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.1%-2.0% with respect to the soap composition.
[0054] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one carboxylic acid has a weight percentage in the range of 0.1%-4.5% with respect to the soap composition.
[0055] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the C8-C18 mono carboxylic fatty acid is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and combinations thereof, and the oxa acid is selected from the group consisting of diglycolic acid, polyglycol diacid, dioxaoctanedioic acid, trioxaundecanedioic acid, and combinations thereof. [0056] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one surfactant is selected from the group consisting of sodium laureth sulfate, decyl glucoside, sodium lauryl sulfate, disodium laureth sulfosuccinate, sodium cocoyl isethionate, sodium lauryl sarcosinate, sodium cocoyl glutamate, sodium cocoyl glycinate, coco glucoside, lauryl glucoside, sodium lauroamphoacetate, and combinations thereof, and the at least one surfactant has a weight percentage in the range of 10%-23% with respect to the composition.
[0057] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one humectant is selected from the group consisting of sorbitol, glycerine, propylene glycol, dipropylene glycol, butylene glycol, and combinations thereof, and the at least one humectant has a weight percentage in the range of 37%-67% with respect to the composition.
[0058] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one electrolyte is selected from the group consisting of sodium chloride, sodium

sulfate, and combinations thereof, and the at least one electrolyte has a weight percentage in the range of 1.5%-3.0% with respect to the composition.
[0059] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one chelating agent is selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), etidronic acid, and combinations thereof, and the at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition with respect to the composition. [0060] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the at least one antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and combinations thereof, and the at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition with respect to the composition.
[0061] In an embodiment of the present disclosure, there is provided a process for preparing a transparent soap composition as described herein, wherein the composition has a pH in the range of 7.0-8.5. In another embodiment of the present disclosure, the composition has a pH in the range of 7.5-8.5.
[0062] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the soap composition provides a clear transparent soap.
[0063] In an embodiment of the present disclosure, there is provided a transparent soap composition as described herein, wherein the soap composition provides a colored transparent soap.
[0064] Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, other implementations are possible.
EXAMPLES
[0065] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless

defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply. [0066] The working examples as described in the present disclosure depicts the desirable parameters of the transparent soap prepared using the components of: (i) at least one alkali metal salt of C8-C18 fatty acid; (ii) at least one alkyl dicarboxylic acid; (iii) at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof; (iv) at least one surfactant; (v) at least one humectant; (vi) at least one electrolyte; (vii) at least one chelating agent; (viii) at least one anti-oxidant; (ix) water; (x) fragrance; and (xi) color in the working ranges of weight percentage. The non-working examples depicts the effect of preparing the soap composition using dicarboxylic acid, monocarboxylic acid and oxa acid having their weight percentages outside the working range. The working and non-working examples were assessed based on the parameters of pH value, transparency, and soap hardness.

[0070] A representative detailed process for preparing the neutral transparent soap has been depicted in the present example.
[0071] A combination of 80.0 g of distilled coconut fatty acid, 50.0g of hysteric acid, 50.0 g of lauric acid, 170.0 g of glycerin, 200.0 g of propylene glycol, 0.3 g of BHT, 0.6 g of tetra sodium EDTA, 0.75 g of EHDP were taken together in a reaction vessel and heated at a temperature of 70℃ with a stirring speed of 100 rpm

until the fatty acid components melt. The temperature was increased from 70℃ to 90℃, and the stirring speed was increased to 130 rpm after complete melting of fatty acids to yield a mixture (part A). The obtained mixture part A was further neutralized with 68.0g of 48% alkali solution to get part B. Post complete neutralization of fatty acids, 25.0 g of sodium chloride in aqueous solution was added followed by the addition of 190.0 g of sodium lauryl ether sulfate, 10.0 g of decyl glucoside and 240.0 g of sorbitol to get part C. To the obtained mixture of part C, 15.0 g of suberic acid, 15.0 g of lauric acid were added to get part D. To the obtained mixture of part D, color components, fragrance and water were added to complete the soap making process. The molten mixture was casted in the molds and allowed to cool to room temperature in order to get desired transparent soap bar.

ene
Tetra
sodium
EDTA 0.06 0.06 0.06 0.06 0.06 0.06
Etidronic
acid (70%)* 0.075 0.08 0.08 0.08 0.08 0.08
Glycerine 20.00 17.00 17.00 15.00 11.00 11.00
Propylene glycol 22.00 20.00 20.00 19.00 20.00 17.00
Sodium
hydroxide
solution
(48%)# 4.77 6.80 7.07 7.78 8.95 8.64
Sodium chloride 3.00 2.50 2.00 1.50 3.00 3.00
Sodium
laureth
sulfate
(70%)^ 20.00 19.00 18.00 18.00 15.00 25.00
Decyl Glucoside
(55%)~ 0.00 1.00 1.50 2.00 0.00 10.00
Sorbitol
(70%)+ 25.00 24.00 20.00 20.00 24.00 9.00
Suberic acid
(un
neutralised) 2.00 1.50 1.30 1.00 0.80 0.50
Lauric acid
(un
neutralised) 1.00 1.50 2.00 2.50 3.00 3.00
Poly
(ethylene glycol) bis (carboxyme thyl) ether (un 0.00 0.00 0.50 1.00 1.50 2.00
22

neutralised)
Fragrance qs qs qs qs qs qs
Colour qs qs qs qs qs qs
Water qs qs qs qs qs qs

Hardness PV in mm 10.0 8.0 7.5 7.0 6.0 5.0
Transparenc
y
+++ Good
++
Acceptable
- Not
acceptable +++ +++ +++ +++ ++ ++
pH (10% Solution at 30 ℃) 7.80 8.00 8.20 8.30 8.50 8.50
‘*’ – For example - 1% of etidronic acid (70%) is equivalent to 0.7% of etidronic acid (100%)
‘#’ - For example - 1% of sodium hydroxide (48%) is equivalent to 0.48% of sodium hydroxide
(100%)
'A' - For example - 1% of sodium laureth sulfate (70%) is equivalent to 0.7% of sodium laureth sulfate 5 (100%)
‘+’ - For example - 1% of Sorbitol (70%) is equivalent to 0.7% of Sorbitol (100%)
'-' - For example - 1% of Decyl Glucoside (55%) is equivalent to 0.55% of Decyl Glucoside (100%)
‘qs’ - quantity sufficient
[0073] The working examples depict a range of pH values as 7.80 to 8.50. Since, 10 the acceptable range of a non-abrasive soap composition as disclosed in the present
disclosure is 7.0 to 8.50, the working examples A1 to A6 are acceptable in terms of
their pH values. The examples A1 to A4 depict good transparency parameter while
A5 and A6 depict acceptable transparency parameter. Therefore, in terms of
transparency all the working examples are acceptable as a neutral transparent soap 15 composition having key attributes. The working examples as depicted herein can
be used for preparation of clear transparent soap and as well as colored transparent
soap bar.
23

Non-working examples Example 4
[0074] The composition of non-working examples A7 to A10 are depicted in
Table 3.
5 [0075] Table 3: Non-working examples

Dicarboxylic
acid
O/R Dicarboxylic
acid
O/R Monocarboxylic
acid
O/R Oxa acid O/R
Ingredients A7 A8 A9 A10
Distilled coconut fatty acid 8.00 8.00 8.00 8.00
Lauric acid 5.00 5.00 5.00 5.00
Hysteric acid 5.00 5.00 5.00 5.00
Butylated hydroxytoluene 0.03 0.03 0.03 0.03
Tetra sodium EDTA 0.06 0.06 0.06 0.06
Etidronic acid (70%)* 0.08 0.08 0.08 0.08
Glycerine 17.00 17.00 17.00 17.00
Propylene glycol 20.00 20.00 20.00 20.00
Sodium hydroxide solution (48%)# 6.80 6.80 6.80 6.80
Sodium chloride 2.50 2.50 2.50 2.50
Sodium laureth sulfate
(70%)^ 19.00 19.00 19.00 19.00
Decyl Glucoside
(55%)~ 1.00 1.00 1.00 1.00
Sorbitol (70%)+ 24.00 24.00 21.00 21.00
Suberic acid (un neutralised) 0.00 3.00 1.00 1.00
Lauric acid (un neutralised) 1.00 0.00 5.00 0.00
24

Poly (ethylene glycol) bis (carboxymethyl) ether (un neutralised) 0.00 0.00 0.00 5.00
Fragrance qs qs qs qs
Colour qs qs qs qs
Water qs qs qs qs

Hardness PV in mm 15.0 20.0 20.0 15.0
Transparency +++ Good ++ Acceptable - Not acceptable ++ - - -
pH (10% Solution at 300C) 9.50 7.00 7.50 8.20
‘*’ - For example - 1% of etidronic acid (70%) is equivalent to 0.7% of etidronic acid (100%)
‘#’ - For example - 1% of sodium hydroxide (48%) is equivalent to 0.48% of sodium hydroxide
(100%)
'A' - For example - 1% of sodium laureth sulfate (70%) is equivalent to 0.7% of sodium laureth sulfate
5 (100%)
‘+’ – For example - 1% of Sorbitol (70%) is equivalent to 0.7% of Sorbitol (100%)
‘~’ - For example - 1% of Decyl Glucoside (55%) is equivalent to 0.55% of Decyl Glucoside (100%)
‘qs’ – quantity sufficient
‘O/R’ – out of range
10 [0076] Referring to Table 3, the example A7 is devoid of a dicarboxylic acid
(suberic acid). A7 although displays acceptable transparency but is high on pH value (9.50) which is beyond the acceptable range of 7.0 to 8.5. Also, it can be observed that A7 is high on hardness as compared to the working examples. [0077] The example A8 comprises 3% of dicarboxylic acid with respect to the
15 total composition. Referring to Table 3, it can be observed that although the pH
value (7.0) is within the acceptable range but the transparency of the soap is not acceptable. Therefore, in spite of being a neutral soap bar, A8 compromises on sensorial parameter of transparency, thus cannot be considered as a working prototype.
25

[0078] The examples A9 comprises 5% of un-neutralized lauric acid (monocarboxylic acid) with respect to the total composition. The working range of un-neutralized carboxylic acid according to Table 1 is 0.1%-4.5%, therefore, A9 has a weight percentage of un-neutralized carboxylic acid beyond the working range. It can be inferred from Table 3 that A9 is a neutral soap bar having a pH of 7.50 (within the working range), but A9 not being a transparent soap bar cannot be considered as a working example of a neutral transparent soap as disclosed in the present disclosure. Also, A9 is high on hardness as compared to the working examples of Table 2.
[0079] The example A10 comprises 5% of oxa acid in an un-neutralized form. According to Table 1, the combined working range of un-neutralized carboxylic acid is 0.1%-4.5% of the total composition. Thus, A10 has a weight percentage of un-neutralized oxa acid beyond the working range. Similar to examples A8 and A9, though the pH value of A10 is within the working range, but the transparency parameter is not acceptable. Thus, the example A10 is not having desirable sensorial feature of transparency and cannot be considered as a working example. [0080] Overall, the non-working examples assert the importance of the weight percentages of the constituents of a neutral transparent soap bar having desirable attributes. In particular, the examples describe the importance of weight percentages of un-neutralized alkyl dicarboxylic acid, un-neutralized monocarboxylic acid, and un-neutralized oxa acid in the neutral transparent soap bar composition. The example A7 has a high pH as it is devoid of alkyl dicarboxylic acid (suberic acid), on the other if suberic acid is present beyond 2% w.r.t. total composition as is depicted in example A8, the composition loses its transparency and thus cannot be considered as an ideal neutral transparent soap bar. Similarly, if the combined weight percentage of un-neutralized carboxylic acid is present beyond the disclosed range of 0.1%-4.5% w.r.t total composition, the obtained composition is not acceptable. The example A9 and A10 comprises higher weight percentage of lauric acid and oxa acid respectively, and loses on the parameter of transparency. Thus, considerable experimentation efforts are involved

at arriving at a desirable neutral transparent soap composition having the desired characteristics.
Advantages of the present disclosure
[0081] The soap composition as disclosed in the present disclosure provides a soap bar having a pH in the range of 7.0-8.5, preferably in the range of 7.5-8.5. The composition involves the presence of un-neutralized alkyl dicarboxylic acid and un-neutralized carboxylic acid (mono-carboxylic acid C8-C18, and oxa acid) in specific weight percentages along with other constituents as disclosed herein in a specific weight ranges to arrive at a desirable composition. The composition as described herein results in a neutral transparent soap bar which is less abrasive on the skin as compared to conventional soap bars. The composition can be used for extended period of time on the skin as it retards the process of removal of skin oil. This property can be attributed to the low pH value of the soap. Thus, it does not affect the acid mantle of the skin and makes the skin less prone to infections and harsh environmental conditions. The present composition can be used to deliver clear transparent soap and also colored transparent soaps. The composition as disclosed herein retains the key attributes of conventional soap bar including mushiness, lather, transparency, and sweating apart from having a low pH. Thus, the composition retains all parameters for commercial acceptance apart from displaying afore-mentioned beneficial qualities.

I/We Claim:
1. A transparent soap composition comprising:
a) at least one alkali metal salt of C8-C18 fatty acid; and
b) at least one alkyl dicarboxylic acid,
wherein the at least one alkali metal salt of C8-C18 fatty acid to the at least one alkyl dicarboxylic acid w/w ratio is in the range of 1:0.0037 - 1:0.154.
2. The composition as claimed in claim 1, wherein the C8-C18 fatty acid is selected from the group consisting of coconut fatty acid, caprylic acid, capric acid, myristic acid, lauric acid, hysteric acid, and combinations thereof.
3. The composition as claimed in claim 1, wherein the at least one alkyl dicarboxylic acid is selected from the group consisting of suberic acid, sebacic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, dodecanedioic acid, and combinations thereof.
4. The composition as claimed in claim 1, wherein the at least one alkali metal is selected from the group consisting of sodium, potassium, and combinations thereof.
5. The composition as claimed in claim 1, wherein the least one alkali metal salt of C8-C18 fatty acid has a weight percentage in the range of 12%-27% with respect to the soap composition.
6. The composition as claimed in claim 1, wherein the at least one alkyl dicarboxylic acid has a weight percentage in the range of 0.1%-2.0% with respect to the soap composition.
7. The composition as claimed in claim 1, wherein the composition further comprises at least one carboxylic acid selected from the group consisting of C8-C18 mono carboxylic fatty acid, oxa acid, and combinations thereof.
8. The composition as claimed in claim 7, wherein the at least one carboxylic acid has a weight percentage in the range of 0.1%-4.5% with respect to the soap composition.

9. The composition as claimed in claim 7, wherein the C8-C18 mono carboxylic fatty acid is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and combinations thereof, and the oxa acid is selected from the group consisting of diglycolic acid, polyglycol diacid, dioxaoctanedioic acid, trioxaundecanedioic acid, and combinations thereof.
10. The composition as claimed in any of the claims 1-9, wherein the composition further comprises: (a) at least one surfactant having a weight percentage in the range of 10%-23% with respect to the composition; (b) at least one humectant having a weight percentage in the range of 37%-67% with respect to the composition; (c) at least one electrolyte having a weight percentage in the range of 1.5%-3.0% with respect to the composition; (d) at least one chelating agent having a weight percentage in the range of 0.01%-0.06% with respect to the composition; (e) at least one anti-oxidant having a weight percentage in the range of 0.01%-0.04% with respect to the composition; and (f) water having a weight percentage in the range of 17%-25% with respect to the composition.
11. The composition as claimed in claim 10, wherein the at least one surfactant is selected from the group consisting of sodium laureth sulfate, decyl glucoside, sodium lauryl sulfate, disodium laureth sulfosuccinate, sodium cocoyl isethionate, sodium lauryl sarcosinate, sodium cocoyl glutamate, sodium cocoyl glycinate, coco glucoside, lauryl glucoside, sodium lauroamphoacetate, and combinations thereof; the at least one humectant is selected from the group consisting of sorbitol, glycerine, propylene glycol, dipropylene glycol, butylene glycol, and combinations thereof; the at least one electrolyte is selected from the group consisting of sodium chloride, sodium sulfate, and combinations thereof; the at least one chelating agent is selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), etidronic acid, and combinations thereof; the at least one antioxidant is selected from the group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and combinations thereof.

12. The composition as claimed in any of the claims 1-11, wherein the composition has a pH value in the range of 7.0-8.5.
13. A process for preparing the transparent soap composition as claimed in claim 1, said process comprising:

a) obtaining at least one alkali metal salt of C8-C18 fatty acid;
b) obtaining at least one alkyl dicarboxylic acid; and
c) contacting the at least one alkali metal salt of C8-C18 fatty acid, and the at least one alkyl dicarboxylic acid to obtain the transparent neutral soap composition.
14. A process for preparing the transparent soap composition as claimed in any
of the claims 1-12, said process comprising:
a) obtaining the at least one alkali metal salt of C8-C18 fatty acid;
b) obtaining the at least one alkyl dicarboxylic acid;
c) obtaining the at least one carboxylic acid;
d) obtaining the at least one surfactant;
e) obtaining the at least one humectant;
f) obtaining the at least one electrolyte;
g) obtaining water; and
h) contacting the at least one alkali metal salt of C8-C18 fatty acid, the at least one alkyl dicarboxylic acid, the at least one carboxylic acid, the at least one surfactant, the at least one humectant, the at least one electrolyte, and water to obtain the transparent soap composition.