Cosmetic composition

Claim 2

An aqueous composition for topical application to human skin which comprises: (i) from 0.01 to 99% by weight of an ester of pyroglutamic acid having the structure: ##STR4## where R is a linear or branched chain saturated or unsaturated alkyl group having from 1 to 12 atoms, ##STR5## or the group: where R' and R" are the same different and are each represented by H or the group: ](CH.sub.3).sub.u' (CH.sub.2 OH).sub.v' (CH.sub.2).sub.2' (CHCH.sub.3).sub.x' (CHOH).sub.y' (CH═CH) .sub.z ] (2) where ]u is zero, or 1 v is zero, or 1] either u or v is 1 and the other of them is zero w is zero, or an integer of from 1 to 21 x is zero, or an integer of from 1 to 4 y is zero, or an integer of from 1 to 2 z is zero, or an integer of from 1 to 4; and u+v+w+x+y+z is an integer of from 1 to 22; the subgroups within the group (2) being in any sequence; provided that when the subgroup (CH═CH) is present, then the total number of carbon atoms in said group (2) will be from 10 to 20; and (ii) from 1 to 99.9% by weight of a cosmetically acceptable aqueous buffer having an effective pH of from 2 to <7; and (iii) from 0 to 98.99% by weight of cosmetic adjuncts.

Claim 3

The composition of claim 1, wherein the ester of pyroglutamic acid is chosen from those where R in Structure (1) is a C 1 to C 12 linear or branched chain alkyl group.

Claim 4

The composition of claim 2, wherein the ester of pyroglutamic acid is selected from the group consisting of: pyroglutamic acid methyl ester pyroglutamic acid ethyl ester pyroglutamic acid n-propyl ester pyroglutamic acid n-butyl ester pyroglutamic acid n-hexyl ester pyroglutamic acid n-heptyl ester pyroglutamic acid n-octyl ester pyroglutamic acid n-nonyl ester pyroglutamic acid n-decyl ester pyroglutamic acid n-undecyl ester pyroglutamic acid n-dodecyl ester pyroglutamic acid iso-propyl ester pyroglutamic acid 2-methylhexyl ester pyroglutamic acid 2-ethylhexyl ester pyroglutamic acid 3,7-dimethyloctyl ester pyroglutamic acid 2,4,4-trimethyl-1-pentane ester pyroglutamic acid methyloctyl ester, and mixtures thereof.

Claim 5

The composition of claim 1, wherein the R group in structure (1) is represented by group (2).

Claim 6

The composition of claim 4, wherein the group (2) is chosen from straight or branched chain, saturated or unsaturated aliphatic groups having from 1 to 22 carbon atoms, or from alkenyl groups having from 10 to 22 carbon atoms.

Claim 7

The composition of claim, 1, in which the ester of pyroglutamic acid is selected from the group consisting of: 2-[pyroglutamoyloxy]-propionic acid methyl-2-[pyroglutamoyloxy]-acetate ethyl-2-[pyroglutamoyloxy]-n-propionate ethyl-2-[pyroglutamoyloxy]-n-butyrate ethyl-2-[pyroglutamoyloxy]-iso-butyrate ethyl-2-[pyroglutamoyloxy]-n-valerate ethyl-2-[pyroglutamoyloxy]-n-caproate ethyl-2-[pyroglutamoyloxy]-n-heptylate ethyl-2-[pyroglutamoyloxy]-n-caprylate ethyl-2-[pyroglutamoyloxy]-n-pelargonate ethyl-2-[pyroglutamoyloxy]-3-hydroxybutyrate iso-propyl-2-[pyroglutamoyloxy]-n-propionate iso-propyl-2-[pyroglutamoyloxy]-n-caprylate n-propyl-2-[pyroglutamoyloxy]-n-propionate n-propyl-2-[pyroglutamoyloxy]-n-caprylate stearyl-2-[pyroglutamoyloxy]-n-propionate 12-hydroxystearyl-2-[pyroglutamoyloxy]-n-propionate stearyl-2-[pyroglutamoyloxy]-n-stearate palmityl-2-[pyroglutamoyloxy]-n-propionate linoleyl-2-[pyroglutamoyloxy]-n-propionate linoleyl-2-[pyroglutamoyloxy]-n-caprylate lauryl-2-[pyroglutamoyloxy]-n-caprylate stearyl-2-[pyroglutamoyloxy]-n-caprylate glyceryl mono(2-[pyroglutamoyloxy]-n-propionate) glyceryl mono(2-[pyroglutamoyloxy]-n-caprylate) glyceryl di(2-[pyroglutamoyloxy]-n-propionate), and. mixtures thereof.

Claim 8

The composition of claim 1, wherein the amount of the ester of pyroglutamic acid is from 0.01 to 20% by weight of the composition.

Claim 9

The composition of claim 1, wherein the buffer is chosen from: a citric acid - sodium citrate buffer having a pH of 4.0 a lactic acid - sodium lactate buffer having a pH of 4.0, and an acetic acid - sodium acetate buffer having a pH of 4.0

Claim 10

The composition of claim 1, which additionally comprises from 0.01 to 10% by weight of a perfume.

Claim 11

The composition of claim 1, which further comprises 0.1 to 50%, by weight of the composition, of an activity enhancer chosen from penetration enhancers, surface active agents and cationic polymers.