Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
  • A61K8/26—Aluminium; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
  • A61K8/27—Zinc; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/36—Carboxylic acids; Salts or anhydrides thereof
  • A61K8/368—Carboxylic acids; Salts or anhydrides thereof with carboxyl groups directly bound to carbon atoms of aromatic rings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/37—Esters of carboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
  • C07C229/52—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the same carbon skeleton
  • C07C229/54—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the same carbon skeleton with amino and carboxyl groups bound to carbon atoms of the same non-condensed six-membered aromatic ring
  • C07C229/60—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the same carbon skeleton with amino and carboxyl groups bound to carbon atoms of the same non-condensed six-membered aromatic ring with amino and carboxyl groups bound in meta- or para- positions
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C255/00—Carboxylic acid nitriles
  • C07C255/01—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms
  • C07C255/32—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms having cyano groups bound to acyclic carbon atoms of a carbon skeleton containing at least one six-membered aromatic ring
  • C07C255/41—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms having cyano groups bound to acyclic carbon atoms of a carbon skeleton containing at least one six-membered aromatic ring the carbon skeleton being further substituted by carboxyl groups, other than cyano groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C309/00—Sulfonic acids; Halides, esters, or anhydrides thereof
  • C07C309/01—Sulfonic acids
  • C07C309/28—Sulfonic acids having sulfo groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton
  • C07C309/44—Sulfonic acids having sulfo groups bound to carbon atoms of six-membered aromatic rings of a carbon skeleton containing doubly-bound oxygen atoms bound to the carbon skeleton
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/41—Preparation of salts of carboxylic acids
  • C07C51/412—Preparation of salts of carboxylic acids by conversion of the acids, their salts, esters or anhydrides with the same carboxylic acid part
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/22—Tin compounds
  • C07F7/2224—Compounds having one or more tin-oxygen linkages

Definitions

• This invention relates to sunscreen agents, that is to say compounds capable of absorbing ultra violet radiation with a wavelength in the range from 290 to 400 nanometres.
• the invention also relates to sunscreen compositions for application to human skin incorporating the sunscreen agents.
• UV ultra-violet
• UV-A rays (320-400nm wavelength) which penetrate deeper into the skin (to the dermis and beyond) .
• Sunscreen compositions should desirably provide protection against both UV-A and UV-B rays, but protection against UV- A rays is particularly desirable, in order to prevent the long term photobiological effects resulting from UV-A radiation.
• sunscreen agents are soluble salts of organic acids such as cinnamate, which incorporate an aromatic nucleus or other conjugates system which provides ultraviolet absorption.
• organic acids such as cinnamate, which incorporate an aromatic nucleus or other conjugates system which provides ultraviolet absorption.
• sunscreen agents are soluble salts of organic acids such as cinnamate, which incorporate an aromatic nucleus or other conjugates system which provides ultraviolet absorption.
• this invention provides a sunscreen composition for application to human skin comprising a cosmetically acceptable vehicle incorporating a salt formed between an organic anion which displays ultraviolet absorption over at least a portion of the wavelength range from 290 to 400 nanometres, and a metal cation characterised in that the metal cation is one or a mixture of aluminium, zinc, titanium, tin, iron or lanthanum and the salt has a solubility of less than 2g/litre in water at 20°C.
• the water solubility of the salts may possibly be less than lg/litre.
• EP-A-557089 there are disclosed insoluble macromolecular salts which are layered double hydroxides in which metal ions are linked through hydroxy groups.
• This invention is particularly concerned with poorly soluble salts which are other than these layered double hydroxides of the formula
• N is one or a mixture of trivalent metal ions
• M is one or a mixture of divalent metal ions or is lithium
• the poorly soluble salts of this invention will frequently be simple salts of a single metal cation so that individual crystals will contain only a single metal. Mixtures of such salts could be used, so that more than one metal is present, but in different crystals.
• the salts of this invention may possibly be devoid of bridging hydroxy groups connecting metal atoms.
• this invention provides use of poorly soluble salts as defined above as sunscreen agents or to prepare sunscreen compositions.
• a third aspect of the invention is the poorly soluble salts themselves as defined above.
• the ultraviolet absorbing anions have a fairly strong absorption in at least a portion of the stated range from 290 to 400 nanometres.
• This may be specified as a requirement that the acid form or a simple alkali metal or ammonium salt of the anion exhibits absorption with a molar extinction coefficient of at least 2 x 10 3 , preferably 3 x 10 3 , more preferably at least 5 x 10 3 and yet more preferably at least 8 x 10 3 over at least a portion of the stated wavelength range from 290 to 400nm.
• the poorly soluble salts of this invention may themselves have molar extinction coefficients of the magnitudes given in the previous paragraph, but it is easier to measure absorbance in solution and thus may be more convenient to specify the extinction coefficient of a soluble salt.
• Effective ultraviolet absorption may be provided by an absorption band whose maximum is outside the stated range.
• the p-methoxy cinnamate ion has an absorption maximum at 285 nanometres but the absorption band is broad enough to provide strong absorption over a range from 290 nanometres up to at least around 320 nanometres.
• absorption in the range 290 to 400 nanometres will be provided by an absorption band with a maximum in the range 260 to 360 nanometres.
• the anions do not have strong absorption in the visible band from 400 to 700 nanometres, especially in the part of it from 450 nanometres upwards, notably from 450 or 500 to 650 nanometres.
• the extinction coefficient for absorption in such ranges may preferably be no greater than 5 x 10 2 throughout the ranges concerned.
• the molar extinction coefficient of a substance is usually measured in solution and is then given by the formula
• I is the intensity of radiation transmitted through the sample
• Iache is the intensity of radiation transmitted through a reference sample consisting of the same solvent but without the substance under test
• c is molar concentration in moles/litre
• the anions which absorb ultraviolet radiation may suitably be one or more of the following:
• Particularly preferred anions are:
• the poorly soluble salts can readily be prepared by precipitation from an aqueous solution of the corresponding alkali metal or ammonium salt, and then separated by filtration.
• the sunscreen compositions of this invention include a cosmetically acceptable vehicle.
• the poorly soluble salts of this invention can be suspended as a dispersion in the vehicle. Preparation may simply consist of adding the poorly soluble salt to the vehicle, and then mixing to form a suspension.
• the vehicle is aqueous.
• the composition is rubbed onto skin and the water then evaporates, along with any volatile organic compounds included in the vehicle. This leaves the poorly soluble salt as a deposit on the skin.
• the aqueous vehicle may be an oil-in-water emulsion with the poorly soluble salt suspended in that emulsion.
• a sunscreen composition according to this invention will contain from 0.05 to 50% by weight of the poorly soluble salt, more preferably from 0.1 to 30% by weight, yet more preferably 2 to 20% by weight.
• the amount which is incorporated will affect the amount of ultraviolet absorption achieved, of course. Therefore amounts towards the upper end of the range would be used for sunscreen compositions intended to give a high degree of protection against ultraviolet radiation.
• compositions according to this invention may be included in sunscreen compositions according to this invention. It is within the scope of this invention to incorporate an additional sunscreen agent. Possibilities include nonionic organic sunscreen agents, inorganic sunscreen agents such as finely divided titanium dioxide and particles of organic polymers.
• sunscreen composition materials which may possibly be included in a sunscreen composition include thickening agents, emollient oils, humectants and fluids to enhance lubricity, notably silicone oils. Minor constituents which may be present include perfume and preservatives.
• X-ray powder diffraction pattern of the product showed major peaks at 12.1A, 6.1A, 5.2A and 3.9A which are characteristic of this material.
• X-ray powder diffraction pattern of the product showed major peaks at 9.9A, 5.16A, 3.52A, and 3.22A which are characteristic of this material.
• the X-ray diffraction pattern of the product showed major peaks at 19.6A, 9.8A, and 6.5A which are characteristic of this material.
• the UV powder reflectance spectra showed a broad absorption band extending from below 250nm to about 340nm and with a tail extending to about 380nm.
• Heat Phase B to 80°C and homogenise. Heat Phase A to 80°C and then slowly add Phase B while stirring. Add in Phase C and then cool to 40°C and add Phase D.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Birds (AREA)
• Epidemiology (AREA)
• Emergency Medicine (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Dermatology (AREA)
• Cosmetics (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10740294

Family Applications (1)

Country Status (4)

Cited By (3)

Citations (2)

• 1993
  • 1993-08-11 GB GB939316646A patent/GB9316646D0/en active Pending
• 1994
  • 1994-08-10 WO PCT/EP1994/002668 patent/WO1995004519A1/en not_active Ceased
  • 1994-08-10 AU AU74990/94A patent/AU7499094A/en not_active Abandoned
  • 1994-08-11 IN IN387BO1994 patent/IN181787B/en unknown

Patent Citations (2)

Non-Patent Citations (1)

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