Hair oil formulation

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 R4 is independently selected from a substituted or unsubstituted C1-6 alkyl group, each R5 is independently selected from the group consisting of a C1-6 alkanediyl group, and Y is a divalent bridging group selected from the group consisting of C1-6 alkanediyl groups and a —R6—O—R7— group wherein R6 and R7 are independently selected from the group consisting of C1-6 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.