Patent GB-804230-A (GB)
Title: Pharmaceutical preparations for application to the skin or the mucous membranes of the mouth
IPC: A61Q19/00
Filed: 1957-01-01
Abstract: Acetals of formula <FORM:0804230/IV (b)/1> where R is the hydrocarbon radical of an alcohol containing 1 to 10 carbon atoms are prepared by reacting a pyridine aldehyde, e.g. pyridine-2-, pyridine-3- or pyridine-4-aldehyde, pyridine-2,6-dialdehyde, with an alcohol containing 1 to 10 carbon atoms, preferably in alcoholic solution using hydrogen chloride as a catalyst.  The pyridine ring may be substituted with halogen atoms, alkyl (e.g. containing 1 to 4 carbon atoms), hydroxyl, alkoxy, aldehyde or carboxylic acid groups. Suitable alcohols are paraffinic, olefinic, cycloparaffinic, cyclo-olefinic, araliphatic or heterocyclic, e.g. b -chloro-ethanol, p-chlorobenzyl alcohol, furfuryl alcohol, menthanol or terpineol. Quaternary compounds may be prepared by reacting the acetal with alkyl halides, e.g. alkyl, iodides or bromides preferably containing 1 to 10 carbon atoms, alkyl sulphates, compounds containing reactive halogen atoms, e.g. dinitrochloro-benzene, or other quaternizing compounds.  Acetals specified are pyridine-2-aldehyde-dimenthyl -, pyridine - 3 - aldehyde - diethyl-, pyridine - 3 - aldehyde - dibenzyl, pyridine - 3-aldehyde - diallyl -, pyridine - 3 - aldehyde - di-menthyl -, pyridine - 2 - aldehyde - dibenzyl-, pyridine - 4 - aldehyde - dimethyl -, pyridine-4 - aldehyde - dimenthyl -, 6 - methyl - pyridine-2 - aldehyde - dimethyl -, pyridine - 3 - aldehyde - glycerol -, pyridine - 3 - aldehyde - diisopropyl -, pyridine - 3 - aldehyde - diisobutyl -, pyridine - 3 - aldehyde - b  - chloroethyl - and pyridine - 3 - aldehyde - ethylene glycol - acetal.  Specified quaternary copounds are N - methyl - pyridinium - 3 - aldehyde - dimethyl acetal iodide, N - (2 : 4 - dinitrophenyl) - pyridinium - 3 - aldehyde - dimethyl acetal chloride, N-methyl-pyridinium-4 - aldehyde - diisopropyl acetal iodide, N-ethyl - pyridinium - 3 - aldehyde - dimethyl acetal iodide, N - ethyl - pyridinium - 3 - aldehyde-dimethyl acetal bromide, and N-propyl-pyridinium-3-aldehyde-dimethyl-acetal iodide.ALSO:Pharmaceutical preparations for application to the skin or to the mucous membranes of the mouth contain 0.01 to 3 per cent by weight of an acetal of formula <FORM:0804230/VI/1> where R is the hydrocarbon radical of an alcohol containing 1 to 10 carbon atoms, and the pyridine ring may be substituted, e.g. by halogen atoms, alkyl, hydroxyl, alkoxy, aldehyde or carboxylic acid groups, or of a quaternary pyridinium compound derived from such an acetal.  The acetal may be obtained by reacting a pyridine-aldehyde, e.g. pyridine-2-, -3-, or -4-aldehyde, pyridine-2,6-dialdehyde or a homologue thereof which is substituted in the pyridine nucleus by at least one alkyl group containing 1 to 4 carbon atoms, with an alcohol containing 1 to 10 carbon atoms, e.g. paraffinic, olefinic, cycloparaffinic, cyclo-olefinic, araliphatic or a heterocyclic alcohol such as b -chloroethanol, benzyl, p-chlorobenzyl or furfuryl alcohol, menthanol or terpineol.  The quaternary compounds may be obtained by reacting the acetal with alkyl halides, e.g. alkyl iodides or bromides, preferably containing 1 to 10 carbon atoms, alkyl sulphates, compounds containing reactive halogen atoms, e.g. dinitrochlorobenzene, or other quaternizing compounds.  Acetals specified are pyridine-2-aldehyde - dimenthyl-, pyridine - 3 - aldehyde - diethyl-, pyridine - 3 - aldehyde - dibenzyl-, pyridine - 3 - aldehyde - diallyl -, pyridine - 3 - aldehyde - dimenthyl-, pyridine - 2 - aldehyde - dibenzyl-, pyridine - 4 - aldehyde - dimethyl-, pyridine - 4 - aldehyde - dimenthyl-, 6 - methyl - pyridine - 2 - aldehyde - dimethyl-, pyridine - 3 - aldehyde - glycerol-, pyridine - 3 - aldehyde - diisopropyl -, pyridine - 3 - aldehyde - diisobutyl-, pyridine - 3 - aldehyde - b  - chloro - ethyl-, and pyridine - 3 - aldehyde - ethylene glycol acetal. Specified quaternary compounds are N - methyl - pyridinium - 3 - aldehyde - dimethyl acetal iodide, N-(2,4-dinitrophenyl)-pyridinium - 3 - aldehyde - dimethyl acetal chloride, N - methyl - pyridinium - 4 - aldehyde-diisopropyl acetal iodide, N-ethyl-pyridinium-3-aldehyde-dimethyl acetal iodide, N-ethyl-pyridinium-3-aldehyde-dimethyl acetal bromide, N - propyl - pyridinium - 3 - aldehyde - dimethyl acetal iodide. Other materials which may be present are gelatin, glycerine, stearin, ethanol, paraffin, olive, nut, pine needle, lavender, lecithin, peppermint and castor oil, cocoa butter, starch, boric and benzoic acid, ammonia, sodium alginate, silicic acid gel, calcium and magnesium phosphate, sodium dodecyl-benzene sulphonate, saccharin, potassium soaps, benzoin tincture, essential oils and 8-hydroxyquinoline sulphate.