the sunscreen preparations provided in accordance with the present invention contain as the essential active ingredient a compound of the formula : ## str2 ## where : r 1 , r 2 , r 3 , r 4 , r 5 , r 6 , r 7 , r 8 , r 9 and r 10 may be the same or different and are hydrogen , alkyl , cyano , nitro , amino , haloloweralkoxy , haloloweralkyl , halo , loweralkoxy , acyl , acyloxy , thio , acylthio , loweralkylthio , loweralkylsulfinyl , loweralkylsulfonyl ; hydroxy , carboxy , and carbalkoxy ; r 3 and r 8 may also be cycloalkyl , cycloalkeny , aryl and heteroloweralkylidenyl . the more preferred compounds for a method of topically treating inflammation embrace those compounds of the formula ii : ## str3 ## where : r 1 , r 2 , r 4 , r 5 , r 6 , r 7 , r 9 and r 10 are hydrogen , alkyl , alkoxy , halo , haloloweralkyl , hydroxy , carboxy , carbalkoxy , and alkylsulfonyl . r 3 and r 8 are hydrogen , alkyl , alkoxy , carboxy , carbalkoxy , halo , cyano , alkylsulfonyl , alkylsulfinyl , haloloweralkyl , phenyl , and cyclohexyl . &# 34 ; alkyl &# 34 ; refers to a loweralkyl hydrocarbon group containing from 1 to about 7 carbon atoms which may be straight chained or branched ; &# 34 ; alkenyl &# 34 ; refers to an unsaturated or partially unsaturated hydrocarbon group containing from 2 to about 7 carbon atoms which may be straight chained or branched ; &# 34 ; cycloalkyl &# 34 ; refers to a hydrocarbon ring having up to about 7 carbon atoms ; &# 34 ; cycloalkenyl &# 34 ; refers to a partially unsaturated hydrocarbon ring having up to about 7 carbon atoms ; &# 34 ; acyl &# 34 ; refers to any organic radical derived from an organic acid by the removal of its hydroxyl group such as formyl , acetyl , propionyl , 3 - carboxy - 2 - propenoyl , camphoryl , benzoyl , toluoyl or heteroyl such as pyridinoyl , piperidonyl , thenoyl , etc . the compounds of this invention may be prepared by the following general procedures . condensation of an aniline derivative with benzaldehyde derivatives or phenyl ketones along the procedures as described by gillman and blatt , organic synthesis , coll . vol . i , 2nd ed ., n . y ., john wiley and sons , pages 80 - 81 will result in the desired product . the following reaction equation illustrates this synthesis : ## str4 ## where r , r 1 , r 2 , r 3 , r 4 , r 5 , r 6 , r 7 , r 8 , r 9 and r 10 are as described above . an alternate method for the production of certain compounds of formula i involves the distillation of a product from a heated mixture of an aryl aldehyde or ketone and an aniline derivative at an elevated temperature and under a reduced pressure . a still further method of preparing certain compounds of formula i would be by condensation of a hindered aryl aldehyde or ketone and an aniline derivative by the azeotropic removal of water . appropriately desired end products having various substituents can be prepared at various stages of synthesis using suitable reactions in order to convert one group to another . thus , for example , using conventional methods , a halogen group can be converted under rosenmund von braun conditions to the nitrile compound . a nitro can be reduced to an amino which can be alkylated to the dialkylamino substituent . an hydroxy compound can be prepared by demethylation of a methoxy substituent . a sandmeyer type reaction can be carried out on an amino compound to introduce a chloro , bromo , xanthate , hydroxyl or alkoxyl group . the xanthate can then lead to the mercapto by hydrolysis , this in turn can be alkylated to an alkylthio group which can be oxidized to alkylsulfinyl and alkylsulfonyl groups . a thiocyanato group may be removed by catalytic hydrogenation . among the suitable compounds which may be utilized in connection with the sunscreen and prostaglandin - inhibiting compositions of the present invention include : these active materials are applied to the skin in combination with a compatible carrier material which may be aqueous , alcoholic , fatty or a combination of these . carrier materials as contemplated herein include those materials generally utilized as a base for sunscreen preparations such as , for example , creams , milks , ointments , gels , oils , lotions , aerosol sprays or the like . such carrier materials , in order to be suitable , must be selected on a basis of their dermatological acceptability and compatibility with the specific active ingredient of the present invention which is utilized . preferred among carrier formulations for the sunscreen agents of the present invention are creams , milk , ointments , lotions and aerosols . examples of suitable carrier materials for the formulation of the sunscreen compositions of the invention include the paraffins , waxes , vegetable or animal oils and fats such as , for example , olive oil , sesame oil , peanut oil and the like , wool fat , spermaceti , esters of fatty acids such as stearic , palmitic and oleic as well as the acids themselves , glycerides of said acids , ethyl , isopropyl , cetyl , stearyl and palmityl alcohols , emulsifying agents of all common types , e . g ., nonionic , anionic or cationic suitable for the preparation of both water - in - oil and oil - in - water emulsions , thickeners such as , for example , the commercially available cellulose ethers , trajacanth , alginic acid or salts thereof and the like . a particularly preferred emulsifying agent is polyoxyethylene stearyl ether having a molecular weight of about 700 and commercially available under the trademark brij j by atlas powder co ., wilmington , delaware . additional additives which may be incorporated into the sunscreen preparations of the invention are preservatives , buffers , ph regulators to adjust the ph thereof to slightly acidic , perfumes , physiologically compatible dyestuffs and the like . other agents which have medicinal or therapeutic value may also be incorported in the compositions of the invention . where the preparations of the invention are in the form of aerosol sprays or foams , suitable conventional propellants , i . e . polyhalogenated hydrocarbons are also included therein . it is contemplated that where the compositions of the invention are in aerosol form , the propellant will comprise about 10 % by weight of said compositions . the concentration of the active sunscreen ingredient in dermatologically acceptable carrier preparations such as contemplated herein is between about 1 % and about 30 % by weight and preferably between about 2 % and about 5 % by weight . wherein the sunscreen preparations of the invention contain mixtures of more than one of the active ingredients , such active ingredients may be combined in any proportions . it is preferred , however , to combine two or more of such ingredients in approximately equimolar concentrations . compositions in accordance with this invention afford excellent protection from the erythemal rays of the sun . additionally , they are effective in preventing and treating painful sunburn . these compositions may be applied freely to the skin . as with any conventional skin treatment preparation , such amounts vary with the exposure conditions , the sensitivity and the pigmentation of the skin of the user , and the like . therefore , the effective amount of the preparations of the invention may be chosen within the discretion of the user . the following examples serve further to illustrate the invention , but are not intended to define or to limit the scope of the invention , which is defined in the appended claims . ______________________________________hydrogenated , ethoxylated ( 10 mol ) lanolin 2 . 0 g . triglyceride of fatty acidof coconut oil 7 . 0 g . cetylalcohol 0 . 6 g . stearylalcohol 0 . 6 g . paraffin oil ( light weight ) 5 . 0 g . n -( o - chlorobenzylidene )- 3 - chloro - 2 - methylaniline 2 . 5 g . stearic acid 3 . 0 g . demineralized water 74 . 0 g . triethanolamine 0 . 8 g . perfume 0 . 5 g . carboxyvinylpolymer 2 . 0 g . conservation agent 2 . 0 g . ______________________________________ a mixture of 2 . 0 g . hydrogenated , ethoxylated ( 10 mol ) lanolin , 7 . 0 g . triglyceride of fatty acid of coconut oil , 0 . 6 g . cetylalcohol , 0 . 6 g . stearyl alcohol , 5 . 0 g . paraffin oil , 2 . 5 g . n -( o - chlorobenzylidene )- 3 - chloro - 2 - methylaniline and 3 . 0 g . of stearic acid was melted at 70 ° c . after addition of 2 . 0 g . carboxyvinylpolymer in 74 . 0 g . demineralized water were added at 70 ° c . with stirring to the resulting suspension . the mixture was stirred for 15 minutes and then cooled . 0 . 8 g . of triethanolamine and 0 . 5 g . of perfume were added at 60 ° c . and 45 ° c ., respectively . the resulting mixture was stirred until cold and a white milk , which was stable at 3 , 000 rpm for 1 hour , was obtained . other lotions identical to that described immediately above are prepared by replacing the n -( o - chlorobenzylidene - 3 - chloro - 2 - methylaniline with any of the active compounds previously mentioned . ______________________________________triglyceride of fatty acidof coconut oil 56 . 3 g . cetylalcohol 2 . 6 g . stearylalcohol 10 . 6 g . paraffin oil ( light weight ) 8 . 0 g . n - benzylidene - p - toluidine 5 . 0 g . demineralized water 12 . 2 g . triethanolamine 0 . 8 g . perfume 0 . 5 g . carboxyvinylpolymer 2 . 0 g . conservation agent 2 . 0 g . ______________________________________ a mixture of 56 . 3 g . triglyceride of fatty acid of coconut oil , 2 . 6 g . cetylalcohol , 10 . 6 g . stearyl alcohol , 5 . 0 g . paraffin oil and 5 . 0 g . n - benzylidene - p - toluidine was mixed at 70 ° c . 12 . 0 g . carboxyvinylpolymer in 12 . 2 g . demineralized water were added at 70 ° c . with stirring to the resulting suspension . the mixture was stirred for 15 minutes and then cooled . 0 . 8 g . of triethanolamine and 0 . 5 g . of perfume were added at 60 ° c . and 45 ° c ., respectively . the resulting mixture was stirred until cold and a lotion , which was stable at 3 , 000 rpm for 1 hour , was obtained . other preparations identical to that described immediately above are prepared by replacing the n - benzylidene - p - toluidine with any one of the aforementioned active compounds . an ointment was prepared by first mixing 5 . 0 g . of p - carboxybenzylidene - 2 - chloroaniline in a hot mixture of 57 . 5 g . of distilled water . 11 . 5 g . of propylene glycol and 1 ml . of concentrated ammonia solution . the resulting mixture was heated to 75 ° c . and added with stirring to a hot ( 75 ° c .) mixture of 17 . 0 g . of glycerine , 4 . 0 g . of a polyoxyethylene stearyl ether having a molecular weight of about 700 . lactic acid was added while the emulsion was still hot in order to adjust to a ph approximating that of the skin , i . e . about 5 . 5 . after cooling , the resulting cream was further worked utilizing a three - roller frame and filled into tubes . the product had excellent properties in protecting the human skin against ultraviolet and visible light rays when spread out over selected areas of the body . an ointment was prepared by first mixing 7 . 0 g . n -( 4 - carbomethoxybenzylidene )- 3 , 5 - dichloroaniline in a hot mixture of 53 . 93 g . of distilled water , 14 g . of propylene glycol and 1 ml . of concentrated ammonia solution . the resulting mixture was heated to 75 ° c . and added with stirring to a hot ( 75 ° c .) mixture of 17 . 0 g . of isopropyl myristate , 4 . 0 g . of glycerine and 4 . 0 g . of a polyoxyethylene stearyl ether , molecular weight about 700 . lactic acid was then added to the hot emulsion to adjust the ph thereof to approximate the ph of the skin , i . e . about 5 . 5 . after cooling , the resulting cream was further worked using a three - roller frame and filled into tubes . an ointment was formed by first mixing 4 . 0 g . n -( 4 - nitrobenzylidene )- 3 , 5 - dichloroaniline in a hot mixture of 60 . 3 g . of distilled water , 11 . 5 g . of propylene glycol and 10 . 1 g . of sodium hydroxide . the resulting solution was heated to 75 ° c . and added with stirring to a hot ( 75 ° c .) mixture of 15 . 0 g . isopropyl palmitate , 5 . 0 g . of glyceryl trioleate and 3 . 0 g . of polyoxyethylene stearyl ether . lactic acid was added to the hot emulsion to adjust the ph thereof to about 5 . 5 . after cooling , the resulting cream was further worked using a three - roller frame and filled into tubes . it had excellent sunscreen properties when applied to the human skin . an ointment was formed as above by first mixing 7 . 0 g . n -( 4 - methylsulfonylbenzylidene )- 3 , 5 - dichloroaniline in a hot mixture of 60 . 83 g . of distilled water , 11 . 5 g . of propylene glycol and 0 . 1 g . of sodium hydroxide . the resulting solution was heated to 75 ° c . and added with stirring to a hot ( 75 ° c .) mixture of 13 . 0 g . polyol diester of capric acid , 5 . 0 g . of isopropyl myristate and 5 . 0 g . of polyoxyethylene stearyl ether . lactic acid was added to the hot emulsion to adjust the ph thereof to about 5 . 5 . after cooling , the resulting cream was further worked using a three - roller frame and filled into tubes . the product had excellent properties when used as a sunscreen . ______________________________________hydrogenated , ethoxylate ( 10 mol .) lanolin 1 . 8 g . triglyceride of fattyacid of coconut 7 . 0 g . cetylalcohol 0 . 6 g . stearylalcohol 0 . 6 g . paraffin oil ( lightweight ) 5 . 0 g . n -( p - carboxylbenzylidene )- 3 - chloro - 2 - methylaniline 0 . 75 g . stearic acid 3 . 0 g . demineralized water 72 . 2 g . triethanolamine 0 . 8 g . perfume 0 . 5 g . carboxyvinylpolymer 2 . 0 g . conservation agent 2 . 0 g . ______________________________________ a mixture of 1 . 8 g . hydrogenated , ethoxylated ( 10 mol .) lanolin , 7 . 0 g . triglyceride of fatty acid of coconut , 0 . 6 g . cetylalcohol , 0 . 6 g . stearyl alcohol , 5 . 0 g . paraffin oil , 0 . 05 g . hydrocortisone and 3 . 0 g . of stearic acid was blended at 70 ° c . after addition of 0 . 75 g . n -( p - carboxylbenzylidene )- 3 - chloro - 2 - methylaniline , 2 . 0 g . carboxyvinylpolymer in 72 . 2 g . demineralized water were added at 70 ° c . with stirring to the resulting suspension . the mixture was stirred for 15 minutes and then cooled . 0 . 8 g . of triethanolamine and 0 . 5 g . of perfume were added at 60 ° c . and 45 ° c ., respectively . the resulting mixture was stirred until cold and a white milk , which was stable at 3 , 000 rpm for one hour was obtained . viscosity : 6000 cp ( brockfield , spindel , 5 , 10 rpm ). 0 . 5 g . of n - 4 - chlorobenzylidene )- 4 - chloro - 2 - methyl - aniline and 0 . 20 g . n -( 4 - hydroxybenzylidene )- 2 - methyl - 3 - chloroaniline are predispersed in 30 . 0 g . of propylene glycol . the mixture is then homogenized into 97 . 4 g . of finished cream , ointment or lotion following a modification of any one of the procedures described in f . w . martin et al , &# 34 ; remington &# 39 ; s pharmaceutical sciences &# 34 ;, 14th ed ., mack publishing co ., easton , pennsylvania ( 1965 ).
compositions for treating radiation induced erythemas and for protecting the human skin against the harmful effects of sunlight , containing as the active ingredient n - benzylideneaniline and its derivatives .