WO2020049585A1

WO2020049585A1 - An efficient and safe non-nano and non-coated spf.

Info

Publication number: WO2020049585A1
Application number: PCT/IN2019/050553
Authority: WO
Inventors: Dhirubhai DESAI
Original assignee: Koel Colours Pvt. Ltd.
Priority date: 2018-09-07
Filing date: 2019-07-27
Publication date: 2020-03-12

Abstract

A non-nano and non-coated sunscreen protection factor (SPF) agent comprising non-nano titanium dioxide and aluminium oxide-hydroxide in a ratio of 99 to 95 : 1 to 5; the agent having a synergistic SPF value of at least 50. It is used in a cosmetic or personal care formulation as well as in the article that require specific and effective SPF value, particularly in the end applications including but not limited to lotion, cream, foundation, lip-stick, nail polish and pressed powder.

Description

TITLE OF THE INVENTION

An efficient and safe non-nano and non-coated SPF.

This application claims priority from Indian Patent Application No. 201821033750 filed on 7th September 2018.

Technical field of the invention:

The present invention relates to an efficient and safe non-nano and non-coated SPF.

It further relates to a process for the preparation of the efficient and safe non-nano and non- coated SPF of the invention, and its use in applications including cosmetics applications.

Background of the invention:

Ultraviolet (UV) light is just a higher energy version of the light which damages our cells and tissues. There are three main types of UV rays:

1. UV-A (320 to 400 nm) rays age skin cells and can damage their DNA. These rays are linked to long-term skin damage such as wrinkles;

2. UV-B (290 to 320 nm) rays have slightly more energy than UVA rays. They can damage skin cells’ DNA directly, and are the main rays that cause sunburns; and

3. UV-C (200 to 290 nm) rays have more energy than the other types of UV rays, but UV-C is absorbed by the ozone layer and does not reach the earth. However, both UV- A and UV-B can penetrate the atmosphere and exposure to them for short period can cause reddening and irritation of the skin. However, prolonged exposure can lead to sunburn, premature skin aging, hair damage (including cataracts), melanoma and other skin cancers. Therefore, it is important to have protection from UV-A and UV-B radiation as a part of personal health care.

The sun protection factor (SPF rating, introduced in 1974) is a measure of the fraction of sunburn-producing UV rays that reach the skin. The SPF is an imperfect measure of skin damage because invisible damage and skin aging are also caused by ultraviolet type A (UVA, wavelengths 315-400 or 320-400 nm), which does not primarily cause reddening or pain. Conventional sunscreen blocks very little UVA radiation relative to the nominal SPF; broad- spectrum sunscreens are designed to protect against both UVB and UVA. According to a 2004 study, UVA also causes DNA damage to cells deep within the skin, increasing the risk of malignant melanomas. ["Induction of the Photoaging-associated Mitochondrial Common Deletion In Vivo in Normal Human Skin", Mark Berneburg et. ah; Journal of Investigative Dermatology; May 2004, Volume 122, Issue 5, Pages 1277-1283]. Titanium dioxide probably gives good protection, but does not completely cover the UVA spectrum, as early 2000s research suggests that zinc oxide is superior to titanium dioxide at wavelengths 340-380 nm.

In general, zinc oxide and titanium dioxide used in the manufacture of SPF are of nano sizes, and are popular in sunscreens and provide sheer sun protection. They are also coated with UV filters like different metal oxides or organic materials like silanes, silicones, organic titanates, fatty acids, metal soaps, polyols, dimethicones, and combinations thereof. To utilise Ti0₂ nano particles in sunscreens, they are normally surface coated with silica, alumina and/or various polymers to (a) increase its stability in the lotion or cream and (b) reduce its photo -activity [Serpone N, et al "Beneficial effects of photo-inactive titanium dioxide specimens on plasmid DNA, human cells and yeast cells exposed to UVA/UVB simulated sunlight." J Photochem Photobiol A Chem. 2006;179:200-212 and Siddiquey IA, et al "The effects of organic surface treatment by methacryloxypropyltrimethoxysilane on the photo stability of Ti02." Mater Chem Phys. 2007;105:162-168.}

A nano particle is a particle of size smaller than 100 nanometers, or 100 billionths of a meter. Defining whether a powder is non-nano or not is actually rather difficult as it is virtually impossible to ensure that a product is 100% nano particle free. Furthermore, many particles are not spherical in shape and thus are difficult to measure.

Friends of the Earth U.S. and Australia have reported that according to the testing results on many popular sunscreens and cosmetic products from the Australian Government’s National Measurement Institute that they are using a potentially hazardous form of a common ingredient anatase titanium dioxide i.e. more than 90 percent of the particles extracted from the products were nano particles. The nano particles of the anatase titanium dioxide have large relative surface area, and are much more reactive than larger particles of the chemical. However, the studies have shown that the anatase form of titanium dioxide (and in particular nano-scale anatase titanium dioxide) can increase the formation of free radicals when exposed to sunlight and water and a number of scientists have questioned the safety of their use in sunscreens and other skin products. Anatase is an aggressive free radical producer compared to rutile, another less reactive form of titanium dioxide used in sunscreens, cosmetics and other products.

Further, Hawaii has passed bill banning sunscreen that can harm coral reefs and will go into effect from January 1, 2021. The legislation prohibits the distribution of sunscreens containing the chemicals oxybenzone and octinoxate that scientists have found contributing to coral bleaching when washed off in the ocean. Reef-safe sunscreen alternatives like Tropic Sport and Raw Elements include mineral sunblocks with zinc oxide and titanium dioxide. They must be“non-nano” in size to be considered reef-safe. If they are below 100 nanometers, the creams can be ingested by corals.

International patent publication no. W02017/210406 claimed a sunscreen composition having synergistic UV protection which comprises the non-nano ZnO and bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT). ZnO used herein is either un-coated or coated with oxide compound e.g. silica or the organic material like silanes, silicones, organic titanates, fatty acids, metal soaps, polyols, dimethicones, and combinations thereof. It has SPF value of at least 15 or a PFA value of at least 8, or both.

Thus, there is a need to develop non-nano and non-coated SPF which is safe, non-toxic and having an effective SPF value, which eliminates the problems associated with the prior arts.

Objects of the inventions:

An object of the invention is to provide a SPF agent which is non-coated and non-nano, particularly titanium dioxide and aluminium oxide-hydroxide, which eliminates the problems associated with the prior art.

Another object of the invention is to provide the SPF agent which is non-coated and non-nano, particularly titanium dioxide and aluminium oxide-hydroxide, which is safe, non-toxic and has an effective SPF value. Still another object of the invention is to provide a process for manufacturing an un-coated and non-nano SPF agent, particularly titanium dioxide and aluminium oxide -hydroxide.

Yet another object of the invention is to provide a sunscreen composition comprising SPF agent of the invention, which is safe, non-toxic and has an effective SPF value.

Yet another object of the invention is to provide a cosmetic or personal care formulation comprising SPF agent or sunscreen composition of the invention, which is safe, non-toxic and has an effective SPF value.

Yet another object of the invention is to provide an article comprising SPF agent, which is safe, non-toxic and has an effective SPF value.

Summary of the invention:

In the presently claimed invention, it is surprisingly found that the aluminium oxide-hydroxide in combination with titanium dioxide, particularly in the ratio of 95 to 99 : 1 to 5 has a synergistic SPF value of at least 50. At the same time, it is non-nano and not coated with additional uv filters. It is manufactured by following simple procedures. Since, the mean particle size of SPF is above 200 nm it is safe and non-toxic. It is used in a sunscreen composition or cosmetic and personal care formulation or article which are safe and non-toxic to the human as well as aquatic eco- system.

Accordingly, in one embodiment, the presently claimed invention is directed to a non-nano and non-coated sunscreen protection factor (SPF) agent comprising non-nano titanium dioxide and aluminium oxide -hydroxide in a ratio of 95 to 99 : 1 to 5; the agent has a synergistic SPF value of at least 50.

Typically, the non-nano titanium dioxide and aluminium oxide-hydroxide is in a ratio of 95 to 97: 5 to 3.

Particualrly, a particle size of titanium dioxide is at least above 100 nm, preferably in the range of 101 to 500 nm, more preferably in the range of 200 to 500 nm, most preferably 300 nm. Accordingly, in another embodiment, the presently claimed invention is directed to a manufacturing process for non-nano and non-coated sunscreen protection factor (SPF) agent according to the invention;

said process comprising the steps of:

a. admixing non-nano titanium dioxide and aluminium oxide- hydroxide in a ratio of 95 to 99 : 1 to 5 by milling;

b. calcinating the mixture at a temperature in the range of 800 to 1000° C for at least 4 hours; and

c. grinding the calcined product by milling to get SPF agent having a mean particle size of at least above 100 nm and a synergistic spf value of at least 50.

Preferably, the non-nano titanium dioxide and aluminium oxide- hydroxide is in a ratio of 95 to 97 : 5 to 3.

Accordingly, in another embodiment, the presently claimed invention is directed to a sunscreen composition for skin, hair and nail care, said composition comprising SPF agent according to invention.

Particularly, the composition is pigmented or unpigmented lotion, cream, foundation, lip-stick, nail polish and pressed powder.

Accordingly, in another embodiment, the presently claimed invention is directed to the sunscreen composition which further comprises UV filter agent or a topically active agent selected from anti-tanning agent, an antimicrobial agent, a depigmentation agent, an anti-aging agent, anti-fungal agent, an insect repellent, photochromic additive and a combination thereof.

Accordingly, in yet another embodiment, the presently claimed invention is directed to cosmetic or personal care formulation comprising SPF agent or sun screen composition of the invention.

Accordingly, in yet another embodiment, the presently claimed invention is directed to an article comprising SPF agent or sun screen composition of the invention. Detailed description of the invention:

The terms“a,”“an,”“the” and similar referents used in the context of describing the invention following claims are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g.,“such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the below-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Specific embodiments disclosed herein can be further limited in the claims using consisting of or / and consisting essentially of language. When used in the claims, whether as filed or added per amendment, the transition term“consisting of excludes any element, step, or ingredient not specified in the claims. The transition term“consisting essentially of limits the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s). Embodiments of the invention so claimed are inherently or expressly described and enabled herein. As used herein, the term "nano" refers to a median primary particle size is smaller than 100 nanometers (i.e. nm).

As used herein, the term "non-nano" refers to a median primary particle size is bigger than 100 nm. Particle size is calculated by measuring the particles in photographs obtained using transmission electron microscopy or scanning electron microscopy. Number weighted distribution of the shortest dimension, when applicable, is used for size analysis and for discussion in this application.

As used herein, the term "weight percent (wt. %)" when used without qualification, typically refers to the weight percent of a particular solid component as compared with all solid components present, excluding medium or vehicle.

As used herein, the term "cream" is typically defined as the composition that does not flow out from a container at 25°C when it is turned upside down.

As used herein, the term "lotion" is typically defined as the composition that flow out from the container at 25°C when turned upside down.

As used herein, the terms "composition" refer to a list of ingredients, and/or components, and can also include list of instructions for preparing and mixing together the ingredients, and/or components to make the composition.

Detailed Description of the Embodiments:

In the following description, the embodiments are described in sufficient details to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical and other changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The detailed description that follows begins with a definition section followed by a description of various embodiments of the invention. A series of examples are presented later followed by a conclusion. Most modem sunscreens contain titanium dixoide (Ti02) and zinc oxide (ZnO) particularly, nano particles of Ti02 and ZnO which are more efficient SPF and blend more easily into the skin than that of their agglomerated form used earlier. However, the recent studies and reviews demands rising concern about penetration of these nano-particles into the skin upon topical application of sunscreen. This may lead to serious health hazardous effects. There are contradictory reviews and studies, both in-vitro and in-vivo; some of them suggests these nano particles do not penetrate intact human skin beyond the stratum comeum, however, some of them are indicating the complete opposite to the earlier suggestions. Another immediate concern is that there is possibility of increased nano particles penetration in compromised skin like sunburned, broken or inflammed skin.

According to the presently claimed invention, there is provided a non-nano and non-coated sunscreen protection factor (SPF) agent. It typically comprises titanium dioxide and aluminium oxide-hydroxide in a ratio of 99 to 95 :l to 5. Preferably, it comprises titanium dioxide and aluminium oxide -hydroxide in a ratio of 95 to 97 : 5 to 3. The titanium dioxide used herein has a mean particle size of at least above 100 nm. In particular, the mean particle size of the titanium dioxide is in the range of 101 to 500 nm; more particularly 200 to 500 nm; more preferaby around 300 nm. Titanium dioxide used herein is either of rutile grade or of anatase grade; preferably anatase. The aluminium oxide-hydroxide (CAS No: 1333-84-2) used has pore volume of 0.8 to 1.0 g/ml and surface area of 250 m /g (minimum). The titanium dioxide used herein is not coated with any additional UV filters or any other additive. The non-nano and non-nano coated SPF has a synergistic SPF value of at least 50. Typically, the SPF value of the SPF agent of the presently claimed invention is at least 50. Typically, it is in the range of 50 to 76.

According to the presently claimed invention, there is provided a manufacturing process for the non-nano and non-coated sunscreen protection factor (SPF) agent of the presently claimed invention. This process comprises the following steps :

a. The titanium dioxide was admixed with aluminium oxide -hydroxide in a ratio of 95 to 99 : 1 to 5 and it was milled further by jet milling to obtain uniform mixture having a mean particle size of 101 to 500 nm; b. The mixture was calcinated in a muffle furnace at a temperature in the range of 800 to 1000° C for at least 4 hours; and

c. The calcined product was ground by jet milling to get SPF agent having a mean particle size of at least above 100 nm and a synergistic SPF value of at least 50.

Typically, the titanium dioxide was admixed with aluminium oxide -hydroxide in a ratio of 95 to 97 : 5 to 3.

Typically, the mixture of step (b) was calcinated in a muffle furnace at a temperature in the range of 800 to 900° C. Typically, the mixture of step (b) was calcinated in a muffle furnace at a temperature 840° C.

Typically, the jet milling of step (a) is carried out at a pressure of 1 to 8 bar and a temperature 5 to l5°C. Typically, the jet milling of step (a) is carried out at the pressure of 8 bar and the temperature 8°C.

Typically, the mean particle size of the SPF agent so obtained in the step (c) is in the range of 101 to 500 nm; preferably 200 to 500 nm; more preferably around 300 nm.

A sunscreem composition comprising the SPF agent of the presently claimed invention and specifically used for skin, hair and nail care. Preferably, the sunscreen composition is either pigmented or unpigmented. It is in the form of a lotion, cream, gel, emulsion, powder depending upon the bases used therein. Preferably, it is in the form of cream, lotion or powder. It is used in the sun-scream, sun-lotion, foundation, lip-stick, nail polish and pressed powder.

Typically, the sunscreen composition of the presently claimed invention, further comprising UV filter agent or a topically active agent selected from anti-tanning agent, an antimicrobial agent, a depigmnetation agent, an anti-aging agent, anti-fungal agent, an insect repellent, a photochromic additive and a combination thereof.

The sunscreen compositions of the present invention may further comprise additional additives like antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrance, humectants, opacifying agents, conditioners, exfoliating agents, pH adjusters, preservatives, natural extracts, essential oils, skin sensates, skin soothing agents, skin healing agents, or the like. See, e.g., The CTFA Cosmetic Ingredient Handbook, Second Edition, 1992, which describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention.

A cosmetic or personal care formulation comprising SPF agent or sun screen composition of the presently claimed invention.

An article comprising SPF agent or sun screen composition of the presently claimed invention.

The present invention is illustrated by the following example, which is not intended to limit the effective scope of the invention.

CHEMICALS USED

1. Titanium dioxide (Anatasc) (Ti0₂ : 97-98%; Tinting Strength:l220 min; Specific Gravity 3.8 - 3.9; Refractive Index 2.5; pH: 6.5 - 8; Bulk Density (tamped) : 0.7 ± 0.2 gm/cm , Mositure: 0.4% max.; Oil Absorption: 20 - 25 gm / 100 gm; and Average Particle Size: 300 to 700 m)

2. Titanium dioxide (Rutile) (Ti0₂ : 93-94%; Tinting Strength: 1750 ± 20; Specific Gravity: 4 - 4.2; Refractive Index 2.7; Rutile Content 99% min.; pH: 7-8.2; Bulk Density (tamped) : 1 ± 0.2 gm/cm³’ Mositure: < 0.3%; Oil Absorption: 18 - 20 gm / 100 gm; and Average Particle Size: 300 to 700 m)

3. Aluminium oxide -hydroxide (CAS No: 1333-84-2: pore volume of 0.8 to 1.0 g/ml and minimum surface area of 250 m /g, particle size of 300 to 400 nm]

Example

We have exemplified the formulae of the SPF agent of the invention in Table 1. Table 1. Example Sunscreen Formulae

Process:

1. The components A, B and C were mixed by jet milling at 8 bar and maintaining temperature at 8° C;

2. The mixture was calcined at 840°C for 4 hours;

3. The calcined product i.e. SPF agent was cooled and further jet milled at 8 bar and maintaining temperature at 8° C to obtain SPF agents 1 to 6.

The SPF agents (1) to (6) were tested for SPF value by COLIPA 2011 and mean particle size by ASTM E2651-13 (Particle size analysis). The results of SPF and particle size are illustrated in Table 2.

Table 2. Test Results of the SPF and Mean particle size for SPF agents (1) to (6)

According to Table 2, SPF value of Titanium dioxide (Rutile), Titanium dioxide (Anatase) and Aluminium oxide -hydroxide with median primary particle size of 300 nm is in the range of 2, 3 and 0 respectivley. Though, Aluminium oxide-hydroxide doesnt have SPF and Titanium dioxide (either Rutile or Anatase form) has SPF of 2 to 3 when tested individually but when SPF agents (1) to (6) comprises both Titanium dioxide (either Rutile or Anatase form) and Aluminium oxide -hydroxide in a particular proportion (99 to 95 : 1 to 5) and prepared according to the process of the invention demonstrate unexpected synergistic SPF value in the range of 50 to 76 at median primary particle size of 300 nm.

The SPF agent having a high SPF 30+ which is a broad spectrum UV protection according to both FDA and Cosmetic Europe regulations, and a ++++ UVA protection rating according to Japanese regulation.

The SPF agent may be further added in the formulation of the sunscreen composition or the cosmetic or personal care formulation or the articles like glass, paint formulation, automobile paint formulation. The quantity of the SPF agent need to be added in the formulation as per the SPF requirement of the formulation. The presently claimed invention facilitates SPF agents which comprises titanium dioxide and aluminium oxide -hydroxide where the median primary particle size of the titanium dioxide is 300 nm and having synergistic SPF value of at least 50, particularly 50 to 76. Thus, the SPF agent of the presently claimed invention is safe and non toxic to human as well as aquatic eco system as well as having effective SPF value. It is converted into the sun screen composition as well as the cosmetic or personal care formulation. It can also be used in the article that require specific and effective SPF value. It is useful in the end applications including lotion, cream, foundation, lip-stick, nail polish and pressed powder.

The present invention has been described with reference to preferred embodiments, purely for the sake of understanding and not by way of any limitation and the present invention includes all legitimate developments within the scope of what has been described hereinbefore and claimed in the appended claims.

Claims

Claims:

1) A non-nano and non-coated sunscreen protection factor (SPF) agent comprising non- nano titanium dioxide and aluminium oxide -hydroxide in a ratio of 95 to 99 : 1 to 5; the agent has a synergistic SPF value of at least 50.

2) The SPF agent as claimed in claim 1, wherein a particle size of titanium dioxide is in the range of 101 to 500 nm.

3) A manufacturing process for non-nano and non-coated sunscreen protection factor (SPF) agent according to any one of the preceding claims 1 to 2;

said process comprising the steps of:

a. admixing titanium dioxide and aluminium oxide- hydroxide in a ratio of 95 to 99 :

1 to 5 by milling;

b. calcinating the mixture at a temperature in the range of 800 to 1000 ⁰ C for at least 4 hours; and

4) A sunscreen composition for skin, hair and nail care, said composition comprising the SPF agent according to the claims 1 to 2 and prepared according to claim 3.

5) The sunscreen composition as claimed in claim 4, wherein the composition is pigmented or unpigmented lotion, cream, foundation, lip-stick, nail polish and pressed powder.

6) The sunscreen composition as cliamed in claim 4, further comprising UV filter agent or a topically active agent selected from anti-tanning agent, an antimicrobial agent, a depigmnetation agent, an anti-aging agent, anti-fungal agent, an insect repellent, a photochromic additive and a combination thereof.

7) A cosmetic or personal care formulation comprising SPF agent or sun screen composition according to any one of the preceding claims 1 to 6. 8) An article comprising SPF agent or sun screen composition according to any one of the preceding claims 1 to 6.