Patent GB-960719-A (GB)
Title: Sunscreen and process of preparation
IPC: A61K8/44
Filed: 1961-07-21
Abstract: Benzanilide compounds of the formula: <FORM:0960719/C1/1> wherein R1 and R2 are hydrogen, C1- 18 alkyl radicals, C2- 18 alkenyl radicals, C2- 18 hydroxyalkyl radicals having 1 to 6 hydroxy groups, C3- 30 etherified hydroxyalkyl radicals having 1 to 6 ether groups, C3- 30 esterified hydroxyalkyl radicals having 1 to 6 ester groups or hydroxyoxyalkylene radicals having from 1 to 40 oxyalkylene units, each oxyalkylene unit having 2 to 18 carbon atoms, wherein R3 and R4 are C1- 6 alkyl radicals or C6- 18 aryl or mixed alkyl aryl radicals, R5 and R6 are hydrogen atoms or C1- 6 alkyl radicals, m1 and m2 are 0 or 1 p1 and p2 are 0, 1, 2, 3 or 4, at least one of m1, m2, p1 and p2 is 1, n1 and n2 are 0, 1, 2, 3 o 4 and x is an integer from 1 to 5, are made by the reaction of an aniline compound having an active amino hydrogen, for example, aniline or an amino benzoic acid or ester with a benzene compound having a carbonyl halide group, for example benzoyl chloride, phthalyl chloride or terephthalyl chloride. The reaction is carried out in an organic solvent which is a good solvent for the reactants and a non-solvent for the product so that the latter is removed from the reaction system as it is formed. Aromatic and aliphatic hydrocarbon solvents are suitable, such as toluene, xylene, benzene, mesitylene, p-cumene, ethylbenzene, pentane, hexane, octane, decane and dodecane.  Temperatures of 50 DEG to 90 DEG C. are suitable.  The acid halide formed during the reaction may be removed by distillation with the solvent or neutralized by addition of an alkaline salt such as sodium carbonate. When the reactants are insoluble in aromatic or aliphatic hydrocarbons, the products may be made by esterification of the corresponding benzamido benzoic acid with an alcohol.  In examples, (1) butyl p-aminobenzoate, (2) isobutyl p-aminobenzoate and (3) n-decyl p-aminobenzoate are reacted with benzoyl chloride forming the corresponding alkyl -N-benzoyl p-aminobenzoates. The products are used in sunscreen compositions.  The formulae of many suitable products are given.ALSO:A sunscreen composition comprises an organic film-forming base (A) and a compound of the formula (B) <FORM:0960719/A5-A6/1> wherein R1 and R2 are hydrogen, alkyl radicals having from 1 to 18 carbon atoms, alkenyl radicals having from 2 to 18 carbon atoms, hydroxyalkyl radicals having from 2 to 18 carbon atoms and from 1 to 6 hydroxyl groups, etherified hydroxy-alkyl radicals having from 3 to 30 carbon atoms and from 1 to 6 ether groups, esterified hydroxy-alkyl radicals having from 3 to 30 carbon atoms and from 1 to 6 ester groups or hydroxyoxyalkylene radicals having from 1 to about 40 oxyalkylene units, each oxyalkylene unit having from 2 to 18 carbon atoms, wherein R3 and R4 are alkyl radicals having from 1 to 6 carbon atoms or aryl or mixed alkyl aryl radicals having from 6 to 18 carbon atoms, R5 and R6 are hydrogen atoms, or alkyl radicals having from 1 to 6 carbon atoms, m1 and m2 are 0 or 1, p1 and p2 are 0, 1, 2, 3 or 4, at least one of m1, m2, p1 and p2 is 1, n1 and n2 are 0, 1, 2, 3, or 4 and x is an integer from 1 to 5. The compositions may be employed in the form of creams, pastes, lotions and solutions.  The sunscreen compound will usually be employed in an amount within the range from 0.5% to 10.0% by weight of the composition.  The sunscreen lotions contain a film-forming base, a solvent and the sunscreen compound.  The creams contain a film-forming base (preferably water-insoluble), an emulsifier, a stabilizer, water and the sunscreen compound. Film-forming bases specified are isopropyl myristate, propylene glycol, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, glycerin, castor oil, lauryl and oleyl alcohols, glyceryl ricinoleates, ethylene glycol and glyceryl laurates, ethylene glycol and glyceryl stearates, isopropyl stearate, butyl oleate, butyl stearate and ethyl oleate. To form creams or heavy lotions, solutions are emulsified with suitable oils and fats such as coconut oils, lanolin, palmitates and stearates.  Detailed examples of clear lotions, a heavy lotion and a cream are given.