Hair oil formulation

1 . A hair care formulation, comprising:

a dermatologically acceptable vehicle;

a dermatologically acceptable oil; and

a deposition aid polymer, wherein the deposition aid polymer is a dextran polymer functionalized with a quaternary ammonium group; wherein the dextran polymer is a branched chain dextran polymer; wherein the branched chain dextran polymer comprises a plurality of glucose structural units; wherein 90 to 98 mol % of the glucose structural units are connected by a-D-1,6 linkages and 2 to 10 mol % of the glucose structural units are connected by a-1,3 linkages; wherein the quaternary ammonium group has formula (B)

wherein

 is a pendant oxygen on the dextran polymer; wherein each R 4 is independently selected from a substituted or unsubstituted C 1-6 alkyl group, each R 5 is independently selected from the group consisting of a C 1-6 alkanediyl group, and Y is a divalent bridging group selected from the group consisting of C 1-6 alkanediyl groups and a —R 6 —O—R 7 — group wherein R 6 and R 7 are independently selected from the group consisting of C 1-6 alkanediyl groups;

wherein the dextran polymer has a weight average molecular weight of 145,000 to 525,000 Daltons; and wherein the deposition aid polymer enhances deposition of the dermatologically acceptable oil from the cleansing formulation onto mammalian hair.

2 . The hair care formulation of claim 1 , wherein the hair care formulation is selected from the group consisting of a shampoo, a conditioning shampoo, a leave on hair conditioner and a rinse off hair conditioner.

3 . The hair care formulation of claim 2 , wherein the hair care formulation is selected from the group consisting of a shampoo and a conditioning shampoo.

4 . The hair care formulation of claim 3 , wherein the deposition aid polymer has a Kjeldahl nitrogen content corrected for ash and volatiles, TKN, of 0.5 to 4.5 wt %.

5 . The hair care formulation of claim 4 , further comprising a hair care cleansing surfactant.

6 . The hair care formulation of claim 5 , further comprising a chelating agent and a thickener.

7 . The hair care formulation of claim 6 , wherein the hair care cleansing surfactant comprises a mixture of sodium lauryl ether sulfate, cocamide monoethanolamine and cocamidopropyl betaine; wherein the chelating agent comprises tetrasodium ethylenediaminetetraacetic acid; and wherein the thickener comprises PEG-150 pentaerythrityl tetrastearate.

8 . The hair care formulation of claim 7 , further comprising a preservative.

9 . A method of depositing oil on to mammalian hair, comprising:

selecting a hair care formulation according to claim 1 ;

applying the hair care formulation to mammalian hair.