Chitosan derivative, method of making the same and cosmetic composition containing the same

Claim 2

CHITOSAN DERIVATIVE CONSISTING OF RANDOMLY DISTRIBUTED PATTERNS OF THE FORMULAE:

Claim 3

Chitosan derivative consisting of randomly distributed patterns of the formulae:

Claim 4

Chitosan derivative consisting of randomly distributed patterns of the formulae:

Claim 5

The process of preparing the chitosan derivative of claim 1, consisting essentially of acylating in an aqueous solution a chitosan salt of hydrochloric or acetic acid, said chitosan consisting essentially of 70 to 95 percent patterns B and 5 to 30 percent patterns A, said aqueous solution of the chitosan salt having a concentration of 1 to 20 percent by weight of said salt, in the presence of a base selected from the group consisting of sodium hydroxide, potassium hydroxide and acid or neutral carbonates of sodium or potassium with a saturated or or unsaturated anhydride of the formula

Claim 6

Process according to claim 2, which includes adding to said aqueous solution of said chitosan salt, alternately and by fractions, said base in dilute aqueous solution and said saturated or unsaturated anhydride of formula III or IV as a powder or in solution in an inert solvent selected from the group consisting of dioxane, tetrahydrofuran and ethyl acetate.

Claim 7

Process according to claim 2 wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium acid carbonate and potassium acid carbonate.

Claim 8

Process according to claim 2 wherein the unsatuated anhydride is selected from the group consisting of maleic anhydride, itaconic anhydride and citraconic anhydride.

Claim 9

Process according to claim 2 wherein the saturated anhydride is selected from the group consisting of succinic anhydride, acetoxysuccinic anhydride, methylsuccinic anhydride, diacetyltartaric anhydride and diglycolic anhydride.

Claim 10

Process according to claim 5 wherein said unsaturated anhydride is present in amounts of 1 to 2 moles of anhydride per equivalent of amine present in the molecule of chitosan.

Claim 11

Process according to claim 6 wherein said saturated anhydride is present in amounts of 0.3 to 2 moles of anhydride per equivalent of amine present in the molecule of chitosan.

Claim 12

Process according to claim 2 wherein said reaction is performed at a temperature between 15* and 30*C.

Claim 13

Process according to claim 2, wherein the product resulting from acylation of chitosan with an unsaturated anhydride is reacted with an amine selected from the group consisting of ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, dimethylamine, diethylamine, ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylentetramine, tetraethylenepentamine, methanolamine, isopropanolamine, diethanolamine, Beta -mercaptoethylamine, glycocoll, alanine, leucine, isoleucine, valine, aspartic acid, glutamIc acid, serine, lysine, cysteine, methionine, cysteic acid, taurine, methyltaurine, penicillamine, glutathion, tryosine and tryptophane, at a temperature between 20* and 60*C for a period of 2 to 140 hours.

Claim 14

Process according to claim 9 wherein said amine is present in amounts of 0.1 to 10 moles per unsaturated pattern present in the chitosan molecule after reaction with unsaturated anhydride.

Claim 15

Process according to claim 10 wherein the reaction mixture is kept for 4 hours at 50*C.

Claim 16

Process according to claim 10 wherein said addition reaction is performed under a nitrogen atmosphere.

Claim 17

Process according to claim 2, wherein the product of the acylation reaction is precipitated by adding an acid to the reaction mixture.

Claim 18

Process according to claim 2, wherein the product of acylation reaction is isolated by adding an organic solvent to the reaction mixture.